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CHAPTER-4
ELEMENTARY STUDENTS’ CONCEPTIONS ABOUT FOOD AND NUTRITION
4.1 Introduction
4.2 Scientific Evolution of the Concept: Food and Nutrition
4.3 Pedagogical Perspective of the concept: Food and Nutrition
4.4 Development of the Concept Maps: Food and Nutrition
4.4.1 The Intended Concept Map: Indian Source
4.4.2 The Intended Concept Map: International Source
4.4.3 The Derived Concept Map: Food and Nutrition
4.5 Students’ Conceptions of Food and Nutrition: Primary Source
4.5.1 General Analysis of Students’ Conceptions about Food and Nutrition
4.5.2 Comprehensive Analysis of Students’ Conceptions about Food and Nutrition
4.5.2.1 Students’ Conceptions about Food and Nutrients
4.5.2.2 Students’ Conceptions about Digestion
4.5.3 Discussion
4.6 Conclusion
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CHAPTER-4
ELEMENTARY STUDENTS’ CONCEPTIONS ABOUT FOOD AND NUTRITION
4.1. Introduction
Food is the source of energy and matter for all organisms and is one of the
links between them. The way we use the term food in everyday language
depends on the context. Text books used in schools describe food in a variety
of ways. There is a lack of an agreed definition of food by scientists (Barker,
1985, as quoted by Francis and Hill, 1993). Food as a concept is fraught with
the semantic problem of the word food having different meanings in everyday
and scientific contexts (Driver et. al, 1994). The school science definition of
food, as organic compounds, which organisms use as a source of energy for
metabolic processes, is not consistently used by science educators. Some text
book authors consider water as food since it has minerals, some do not since
water is not organic. Nutrition is the process by which living organisms obtain
food and use it for growth, metabolism and repair. The stages of nutrition
include ingestion, digestion, absorption, assimilation and excretion. Food
provides matter and energy to the plants and animals and is the link between
inanimate things like gases, minerals, water etc and the living world. Food and
nutrition is an important component of Biology linked with Human Physiology,
Ecology, Nutrition and Dietics and other similar subjects.
The concept of food and nutrition is introduced from early elementary classes
and even to pre-primary children since it is integrally linked to our well-being
and health. While the sub concepts of variety of food, healthy food and junk
food, hygiene, healthy food habits are part of primary classes; components of
food, role of various nutrients in human body, plant nutrition, digestion and
nutrition in animals (humans), management of food resources etc are part of
upper elementary curriculum.
83
The following section traces the evolution of the concept of food and nutrition
historically from the time of Hippocrates.
4.2. Scientific Evolution of the Concept: Food and Nutrition
The concept of Food and Nutrition has been evolving since 400 BCE when
Hippocrates said that food has a positive effect on our health and well being.
But the major ideas evolved since mid of eighteenth century till the present.
Around 1770, Antoine Lavoisier, the “Father of Nutrition and Chemistry”
discovered the details of metabolism demonstrating that the oxidation of food is
the source of body heat. In 1790, George Fordyce recognized calcium as
necessary for fowl survival. In the early 19th century, the elements- carbon,
nitrogen, hydrogen and oxygen were recognized as the primary components of
food, and methods to measure their proportions were developed.
In 1816, Francois Magendie discovered that dogs fed only with carbohydrates
and fat lost their body protein and died in a few weeks, but dogs also fed with
protein survived, identifying protein as an essential dietary component. In 1747,
Dr. James Lind a physician with British Navy discovered that the sailors who
were given limes were saved from scurvy while others suffered. Vitamin-C was
discovered much later in 1930’s as a vital nutrient. It was discovered in early
1800s that food is composed mainly of four elements: carbon, hydrogen,
oxygen and nitrogen. J. Leibig of Germany was the first to point out chemical
makeup of carbohydrates, fats and proteins in 1840. One by one all vitamins
were discovered in early 20th century. Since 1950s to the present, the role of
essential nutrients as part of bodily processes has been brought to light.
Fibre became a household word back in 1970s when Dr. Denis Burkitt, a man
nicknamed the Fibre Man, and his colleagues made “the fibre hypothesis” that
states that fibre can prevent certain diseases. Through their work in Africa, they
discovered that diseases that were common in the Western cultures were not
common there. These included heart attacks and high blood pressure
(cardiovascular diseases) obesity and diabetes (metabolic disorders), intestinal
problems (constipation, gallstones, appendicitis and colon cancer), varicose
84
veins and blood clots (deep vein thrombosis). The primary dietary difference
was the high intake of fibre and low intake of refined carbohydrates in the
African population. Burkitt also noted the emergence of these diseases in the
United States and England after 1890 following the introduction of a new milling
technique that removed fibre from whole grain flour to produce white flour. More
became known about the role of vitamins and minerals as components of
enzymes and hormones that work within the body. Synthetic enzymes and
vitamins were synthesized.
The idea about human nutrition kept evolving since the ancient anatomists.
Ancient and medieval anatomists had fairly accurate gross physiological
knowledge of the structure of stomach, intestines and colon. They recognized
the importance of digestion as a key aspect of maintaining the humoral balance
of the body. Initially medical practitioners viewed the stomach as an active,
almost thinking agent in the body. Galen additionally described it as a store
house of nutrition that sorted the ‘wheat from the chaff’ meaning that stomach
has a filtering effect also. In the Galenic tradition, it was the site of first
digestion, since the body digested nutrients in multiple ways. Every aspect of its
shape and texture – even its location – facilitated this process. Master Nicolaus
in the twelfth century poetically wrote: “The stomach has the liver below it like a
fire underneath a cauldron; and thus the stomach is like a kettle of food, the
gall-bladder its cook, and the liver is the fire.” Similarly, the names of parts of
the digestive system recalled their specific functions. Many thought that the
colon was a colander that strained the faeces.
Increased dissection led to more detailed descriptions of the organs involved in
digestion and illustrations were drawn of the organs and their internal
structures. Leonardo da Vinci believed that the digestive system aided the
respiratory system in its function. In the mid-seventeenth century, a Flemish
physician Helmont offered the first chemical account of digestion and placed
emphasis on the stomach as a chemical laboratory (known as alchemist theory
of medicine).
85
By 1825, Dr. Beaumont began to experiment on digestion using an open
wound in the stomach of St. Martin, a wounded soldier. Dr. Beaumont worked
on the samples of stomach to digest bits of food in cups. This established that
digestion was primarily a chemical process and not a mechanical one. In 1835,
German physiologist Theodor Schwann discovered the non-acidic component
of gastric juice which he named pepsin (to digest’ in Greek) which was later
shown to be an enzyme. In 1897, another German scientist, Eduard Buchner,
discovered by accident that fermentation actually does not require the presence
of living yeast cells. Buchner made an extract of yeast cells by grinding them
and filtering off the remaining cell debris. Then he added a preservative-sugar
to the resulting cell-free solution to preserve it for future study. He observed that
fermentation, the formation of alcohol from sugar, occurred. Buchner then
realized that living cells were not required for carrying out metabolic processes
such as fermentation. Instead, there must be some small entities capable of
converting sugar to alcohol. These entities were enzymes. Buchner’s accidental
discovery won him the 1907 Nobel Prize in Chemistry.
Thus, scientific methods of inquiry, imagination of brilliant minds, in addition to
discovery of technological instruments have helped humanity develop an
understanding about food and nutrition (Refer to figure 4.1).
From the timeline of food and nutrition, it is understood that evolution of food
and of nutrition occurred independently. Evolution in food and digestion
stemmed from speculation: speculation about effects of food with health,
speculation about role of different organs or glands in the body. Interpretation of
observations of experimentations leads to generalisations such as those of Dr.
Beaumont. From the study of the evolution of food and nutrition, the
implications for school science is that alternate conceptions of students are
important starting points for subsequent scientific understandings. Students
may comprehend generalisations about food and nutrition from explanation of
experiments and subsequent theory-building. Learners would probably
understand and describe concepts related to food first, and then understand
nutrient of food. Explaining or emphasising the need of including a component
86
or nutrient into diet may not useful for learners till they comprehend the
biochemical nature of its transformation inside the body. Hence the attention of
students also needs to be drawn to conceptual explanation behind chemical
transformation of food, absorption and assimilation.
Fig. 4.1: Time Line – Food and Nutrition
4.3. Pedagogical Perspective of the Concept: Food and Nutrition
Food and digestion is a topic fundamental to most science curriculum and a
core concept of living things. Digestion relates to other major life processes
Food and Nutrition
400-BC-Hippocrates-food has
positive effect on our health
1567-Helmont-Given an account
about digestion
1651-Harvey-Living things
Originate from eggs.
1747-James Lind-
Discovered Vitamin C
1770- Antoine Lavoisier-
Became father of nutrition
and Chemistry
1790- George Fordyce-
Recognized calcium
Francois-1816- Invented
the importance of dietary
protein
1840-J.Leibig- Chemical
makeup of carbohydrates
1897- Eduard Buchner-
invented enzyme
1905- William Fletcher- Identified the
role of essential nutrients Dr. Denis Burkitt- Invented
fibers and its use full ness
for good health
87
such as respiration, circulation, excretion and growth. Therefore teaching of this
concept requires particular attention in science education. Food, eating and
digestion are inter-related concepts and curriculum places emphasis on the
development of knowledge and attitudes in school children that are conducive
to healthy nutrition and living.
The historical evolution of the concept of food and nutrition has shown that a
complete understanding of nutrition is an ongoing endeavour on the part of the
scientific community comprising of nutrition specialists, molecular biologists,
medical practitioners, chemists among others. Sophisticated concepts of food
and human nutrition have emerged as part of interdisciplinary research. The
discovery of various aspects of food and nutrition over the human history has
helped humans have a cogent area of knowledge about human nutrition.
Though new discoveries are being made about the role of enzymes, or proteins
or other bio-molecules, they are at the ultra-cellular and at times sub-atomic
level and pertain to medical sciences and not the science teaching till
secondary level per se. Understanding the pedagogical aspect of the concept
of food and nutrition would help the researcher to build a more complete
comprehension of the difficulties if any in the understanding of the concept by
elementary students and to finalise the conceptual statements based on which
questions would be framed. Much of children’s ideas about food and digestion
have been compiled in the research summary developed by Leeds National
Curriculum Science Support Project, 1992 with the aim to help teachers.
Pedagogical perspective has been collated from the above summary and other
research conducted by nutritionists, and other researchers from the perspective
of science education or child development.
Children and most adults consider food as that which is fit for human
consumption; i.e, food is something which is eaten. They usually extend it to
mean anything useful taken into an organism’s body, including water, minerals.
From an early age, children seem to know that eating has many consequences:
growth, health, strength and energy. From the age of eight, most children
differentiate different kinds of diets as making people fat or strong. Contento
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(1983) found that children in concrete operational stage can classify concrete
items such as foods into groups and understand that food is changed in some
way in the stomach, but they do not know how the effect was brought about.
In the everyday context, children and most adults think food as something we
eat. Food is thought of as solid and not drinks/beverages. Learners identify
food as material to provide growth, health and activity. They do not recognise
that food is source of material to become part of their bodies in growth or that
food is source of energy. Children( 5 to 11 years) do not refer to a transfer of
matter from the environment to the organism, though some children do explain
the growth of animals by stating that the organism has to ‘stretch’ to make room
for the food eaten( Russell and Watt ,1989). Smith and Anderson (1986)
suggested that many 11 to 12 year olds conceptualise food as something that
can be created and destroyed, and converted directly into energy. According to
Barker (1986), older secondary school students’ use of edibility and palatability
as criteria of food gets replaced by the energy criterion. The benefits of eating
food to organisms are seen as an example of cause-effect reasoning rather
than as a transformation of matter from one form to another.
From an early age, children, know that what we eat consists of proteins, fats,
vitamins etc, but they do not understand function of these substances and do
not recognise them as groups of materials. They do not distinguish the food we
eat from the components, for example, they have the notion that bread is
starch, pulses are protein etc. They may not understand the cellular or
molecular nature of food (Simpson, 1984).
Young children have various notions about their body parts like stomach and
digestion of food .They imagine their body to be hollow bag, which is all
‘stomach’ containing food, blood and wastes (Gellert, 1962). The youngest
children relate the stomach to breathing, blood or strength and energy. From
about seven they begin to know that the stomach helps to break or digest food,
and later that food is transferred elsewhere after being in the stomach and by
age 9, most children listed several organs including the stomach. Older children
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realise that there is a food bag inside the body, but use ‘stomach’ to apply to
both stomach and abdomen. Gellert, 1962 found that by 11, most children had
a fairly correct outline of anatomy and the overall function of systems. She
attributed the initial ideas to sensations of heartbeat and swallowing, and later
ideas to TV and hospital experience. Many think that digestive system has two
outlets, one for feaces and one for urine.
A very common concept amongst children is that digestion is the process which
releases usable energy from food. This arises from linking the two acceptable
ideas ‘energy’ is obtained from food’ and ‘digestion is the breakdown of food’ to
construct an unorthodox idea.
Simpson (1984) found that at thirteen, children’s ideas of the sequences of
digestion are very confused, both in terms of the anatomical route and the
processes. Routes may include the trachea, heart, kidneys in some children’s
minds. The sequence of processes may start with breaking into soluble
particles, releasing energy, followed by swallowing. These ideas are not naïve
intuitive notions but construction derived from an overload of information. Pupils
have been taught a lot of unfamiliar words or familiar words in a new context.
Leeds National Curriculum Science Support Project (1992) researched and
reviewed existing research into children’s ideas about nutrition and concluded
that the challenge for elementary students is to accept that digestion is not an
end in itself but an intermediate stage between eating and building new body
substances or releasing energy. The challenge can be tackled at two levels: (1)
working and refining everyday words connected with digestion into scientific
meanings. (2) for a deeper level understanding, developing the concepts of
conservation of matter and matter being rearranged. Further, understanding of
digestion depends on previously established concepts of solids, liquids and
solubility.
Assimilation of food is central to understanding much of biology (Driver, 1994).
Conceptual understanding in most aspects of nutrition would be achieved if
learners understand that what we eat actually becomes skin, bone, blood etc
90
(and what plants make, becomes leaves, wood etc.). Understanding bio-mass
may be a useful step for learners to realise that bio-mass consists of products
of chemical interactions and may act as reactants in further chemical
interactions. Once learners have developed particle ideas, they may be able to
integrate assimilation with rearrangement of atoms.
Table 4.1: Investigators Studying Conceptions of Elementary Students about various Food and Nutrition Concepts
Sub-concepts of Food and Nutrition
Investigators
Below 9
yrs
4th
(9 yrs)
5th
(10 yrs)
6th
(11 yrs)
7th (12 yrs)
8th
(13 yrs)
Nutrients in Food Arnold and Simpson (1980)
Food-Concept Barker (1985) � � � � �
Consequences of food Carey S. (1985) � � �
Food – source of energy Leach, Driver et al. (1992)
� � � � � �
Food-source of energy Francis and Hill (1993)
�
Classification, importance of nutrients
Sheila Turner (1997) � � �
Nutrients and health Dixey, Sahota et al. (2001)
� � �
Food groups, nutrients & health
Hart,Bishop and Truby (2002)
� � � �
Digestive organs and their role
Gellert (1962) � � � � � �
Enzymes egestion Simpson (1984) �
Respiration & digestion Nunez and Banet (1997)
� � �
Structure & function of D.S Texeira (2000) � � �
Digestive system Reiss and Tunnicliffe (2001)
� � � � � �
Digestion process,circulation
assimilation Carvalho (2004) � � �
Digestion process Cakici Y. (2005) � �
Digestive system-figure Mathai and Ramadas (2009)
� � �
Digestive system & respiratory system-figure
Susana Gracia-Barros et al. (2011)
�
91
Researchers have researched into students’ conceptions of food and nutrition
using techniques and tools according to various perspectives starting from pre-
primary children to adults (Table 4.1). From all the available research in the
area of elementary students’ understanding of food and nutrition concepts, one
can infer that research on food is a strand separate from the nutrition strand.
Mostly researchers have investigated in either of the strand. Researchers have
investigated on the sub-concepts of meaning of food as perceived by learners,
classification into food types, importance of nutrients in our body and impact of
food on health. Within the digestion and nutrition strand, the sub-concepts
investigated are about the structure of digestive system, understanding about
role of mouth, stomach intestines etc., and concepts about assimilation,
absorption and the relation between concepts of energy, matter and digestion.
The concepts investigated with youngest children are often, meaning and
classification of food (Contento, 1983), structure of digestive system (Gellert,
1962) and children’s perceptions about nutrition and growth (Leach et al., 1992)
and conceptual understanding about relation between digestion and other life
processes are investigated of older learners (Table 4.1) .
Learners are able to relate to concepts of food easily than those of nutrients
which needs understanding about particulate nature of matter. The challenge
for elementary students is to accept that digestion is not an end in itself but an
intermediate stage between eating and building new body substances or
releasing energy. This would be progression of learners towards sophisticated/
integrated food and nutrition concepts which seems difficult at the elementary
level without pedagogical efforts directed towards that end.
Having known the conceptual resource of learners from the pedagogical
perspective about food and nutrition prepares the researcher to develop
questions to generate primary data.
92
4.4. Development of the Concept Maps: Food and Nutrition
Concept maps were developed to fulfil the following objectives:
a. To understand what the intended curriculum includes in the area of food
and nutrition in Indian context
b. To identify what constitutes ‘standard’/expected knowledge in the area from
available curricular resources and
c. To derive a concept map from the maps at a) and b) above and to form a
basis for developing questionnaire
Concept maps can be defined as visual representations that are added to
instructional material to communicate the logical structure of the instructional
material. The concept map serves as a device to illustrate the hierarchical
conceptual and propositional nature of knowledge. The concepts are arranged
in a hierarchy with a super ordinate concept at the top. The concepts are linked
by lines labelled with connecting words that form the proposition uniting the
concepts. Concept mapping requires the mapper to prioritise and make
judicious use of selected concepts when mapping (Novak and Gowin 1984). It
involves identification of concepts in study materials and their organisation from
the most to least general and more specific concepts.
Concept maps are flexible tools that can be used in a variety of educational
settings (Stewart, Van-Kirk and Rowell, 1979).They have been used as a tool
for assessing meaningful learning (Novak, 1979) as well as in curriculum
planning, instruction and evaluation( Stewart et al,1979).Concept maps are
useful in science curriculum planning for separating significant from trivial
content (Starr and Krajcik, 1990) and focussing the attention of curriculum
designers on teaching concepts and distinguishing intended curriculum from
instructional techniques (Stewart et al, 1979). Science educators extract, select
and prioritize concepts from information-dense materials (Jonassen, Biessner
and Yacci, 1993). Science education reforms have developed concept maps to
decide which concepts are the most important to learn and use what are
important concepts that contribute the big picture or pervasive principles at the
93
core of scientific disciplines. Science curriculum reforms in USA and Australia
are such cases and are being presented in the following paragraphs.
AAAS Project 2061 and the National Science Teachers Association (USA)
published two volumes of Atlas of Science Literacy including nearly 100 maps
which chart all the learning goals specified as ‘Benchmarks’ essential for every
student to learn. The maps given in the Atlas of Scientific Literacy illustrates the
relationships between individual learning goals and shows the growth of
understanding of ideas. Connecting arrows indicate the connections between
ideas which are based on the logic of the subject matter (or on cognitive
research about how students learn). The maps are available at
http://www.project2061.org//tools//benchol/bolframe.html.
The Department of Education and Early Childhood Development (DEECD),
State Government of Victoria, Australia has developed the science continuum
P-10 for effective science teaching. The Science Continuum P-10 identifies
focus ideas at each level of essential learning standards for science.
Connections between concepts and pathways of student’s conceptions are
mapped in science concept development maps. The concept developmental
pathways are the ones students may take when developing scientific
understandings. They demonstrate the relationship between concepts and their
contribution to a range of scientific fields and the increasing complexity
developed from more simple understandings. The concept maps are available
at www.education.vic.gov.au/studentlearning/teachingresources/science.
The development of concept maps of Food and Nutrition was taken up by
analysing (a) the Environmental Science Text books (class 3rd to 5th) and
Science Textbooks of NCERT (class 6th to 8th) and (b) International standards
in science and other curricular material available through web resources.
4.4.1. The Intended Concept Map: Indian Source
In our country NCERT is an apex body under the Ministry of Human Resource
Development (MHRD) which is responsible for preparing curriculum guidelines
94
for the entire country. It also develops and publishes text books based on the
guidelines prescribed in the National Curriculum Framework. Since education is
in the concurrent list, most of the states, develop their own curricular material
based on the national curriculum framework. Some of the states adopt the
NCERT textbooks translating it in regional languages (e.g. as in case of Delhi
State) and other states adopt them to suit their local contexts. With an
experience in the field, the researcher has found that private publishers or
publishers of the state board mostly develop text books in the same lines as the
NCERT textbooks and hence NCERT textbooks were selected as symbolic
source of intended curriculum in the Indian context The syllabus guidelines for
elementary classes for environmental studies (from class 3rd to class 5th) and
science (from class 6th to 8th) were looked into. At the primary level, science is
part of environmental studies and not as a separate subject. At the upper
primary level science is taught as a compulsory subject. The textbooks from
class 3rd to 8th and syllabus guidelines of elementary classes were analysed to
derive a concept map. The syllabus guidelines and textbooks are available at
www.ncert.nic.in. After Starr and Krajcik (1990), significant content was
separated from trivial content to focus the attention on teaching concepts and
distinguishing intended curriculum from instructional techniques (Stewart et al,
1979) to draw the concept map.
The outline of the concepts and sub concepts of food and nutrition has been
drawn in the coming sections (refer to Figure 4.2). To understand the
placement and depth of the concepts in each grade, the researcher identified
the following ‘conceptual dimensions’ (Savinainen and Scott, 2002; Stevens et
al, 2009) / strands under the concept food and nutrition. Ideas that describe
concepts related to, or necessary for understanding food and nutrition were
collected and categorized within these conceptual dimensions or strands.
Because of the nature of the field, many ideas fall into multiple dimensions, but
are considered in any one dimension while analyzing.
95
Fig. 4.2: Concept Map on Food and Nutrition – From Intended Curriculum: Indian Source (Developed by the Researcher)
FOOD & NUTRIENTS
Food choices/preferences,
Hunger
Sources of food: Plants-potato
and corn, animal foods, Honey,
Eggs Plants-food from leaves,
flowers, root etc.
Food: various types of
animals, goat and snake etc.
Variety of food eaten
during journey
Community lunch at
Gurudwara
Jaggery,
Amla, Leafy
Vegetables to
cure anemia
Plant parts and animal
products as food
Components of food –
carbohydrates, fats,
proteins, vitamins and their
role, deficiency diseases
DIGESTION
Teeth help in eating
Animal, Teeth and their functioning
Digestion begins in the mouth stomach
in digestion, hunger, junk food glucose
drip (Taste buds & tongue)
Animal nutrition: digestive system-
human digestion of carbohydrates,
proteins and fats by digestive
juices, digestion process –
ingestion, digestion, absorption-
assimilation-egestion
Aerobic and anerobic
respiration, cellular respiration,
food-respiration, energy
products like alcohol, water,
lactic acid or carbon dioxide
AGRICULTURAL
PRACTICES
Some food crops,
how they are grown
implements
Change in
agricultural practices
Plant nutrition: photosynthesis
heterotrophic plant nutrition,
parasites, insectivorous plant,
saprotrophs
Crop production: basic practices
implements, fertilizer and
manure management and storage
Digested food circulated
through circulation system
96
The major strands under consideration are:
• Food-nutrients, micronutrients, balanced diet
• Human digestive system-parts, functions of organs, digestion process.
Each strand was traced in the context of all chapters presented in the textbooks
of Class 3rd to 8th related to food and nutrition concept.
The concepts of food and nutrition were analysed in EVS and Science
textbooks of NCERT from classes 3rd to class 8th. The concept food has been
given a major place in the present curriculum designed by NCF, 2005. It is one
of the 7 given themes which form the core of both EVS and science syllabus in
primary and upper primary classes. The concept of food is introduced from
class III with topics on food of animals, various plant parts we eat, various
methods and utensils used for cooking, various methods of preserving food and
how food crops are grown in primary classes .The topics included under
nutrition at this level are types of teeth, digestion of food, anaemia and food,
glucose drip etc. The topics are dealt in the social context. At the upper primary
level the topics included under food are various components of food, balanced
diet, crop production, plant and animal sources of food etc and the topics under
nutrition are autotrophic and heterotrophic nutrition, animal nutrition, digestive
system in humans, digestion of carbohydrates, proteins and fats by digestive
juices, digestion process – ingestion-digestion, absorption, assimilation,
egestion, aerobic and anaerobic respiration, cellular respiration, food---
respiration – energy, products like alcohol, water, lactic acid or carbon dioxide,
digested food circulated through circulatory system.
Concept statements about Food and Nutrition included in elementary classes
as given in NCERT textbooks are as follows:
• Our food is derived from various plant parts and animal sources.
• We have different types of teeth to chew, bite and cut food.
• Digestion of food takes place in the different organs of the digestive system.
• Carbohydrates, proteins, fats, vitamins and minerals are important
components of our food.
97
• Each component has an important role in providing energy, to build our
body and metabolism.
• Nutrition includes intake of food i.e. ingestion, digestion, absorption,
assimilation and egestion.
• Digested food is absorbed into the blood and circulated in the body through
circulatory system.
• Digested food gives energy through respiration.
• Respiration is of two types: aerobic and anaerobic.
• Organisms are autotrophs or heterotrophs depending on whether they make
their own food or not. Types of Heterotrophs, Insectivorous Plants
• Plants and Animals - Food Sources; Modes of Food Intake; Variety of Food
• Food gets spoiled if not stored properly.
The concept map developed by the researcher to show the hierarchy of
concepts included in the text books of NCERT elementary level is placed at
Figure 4.2. The concept map shows presentation of concepts in the upper
primary level compared to primary classes. There are many concepts to be
conceptualised within a short span of 3 years of upper primary level.
4.4.2. The Intended Concept Map: International Source
There are several concept maps available in text books and websites on the
concepts of food and human nutrition, but most maps are separate showing
hierarchical representation of the concepts of either food or nutrition along with
connecting ideas (Figure 4.3 & 4.4). The researcher has found the intended
concept maps from the international sources showing the concept of food and
nutrition starting from the concept of nutrients of food and extends up to
biochemical breakdown of food by enzymes and assimilation. The concepts
and sub concepts are scientifically stated. With standards movement in
countries like USA, UK, Australia, New Zealand, there is focus on scientific
literacy (Duit, 2007) of students. Science curricula are presenting hierarchical
progressions in a topic which follow one another as children learn about and
investigate in a broad span of 6-8 years (Ducshl et al, 2007).
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Source: http://www.slideshare.net/dhmcmillan/food-and-digestion-concept-map-presentation
Fig. 4.3: Concept Map on Food from Web Resource
Source: http://www.google.co.in/imgres?imgurl=http://shida810.files.wordpress.com/2010/10/digestion.jpg
Fig. 4.4: Concept Map on Digestion from Web Resource
99
The progression maps from other sources shows the concept of energy and
matter integrated with food and nutrition which is scientifically stated but is left
to scaffolding by the teachers to relate to the context of the learners.
4.4.3. Derived Concept Map: Food and Nutrition
A concept map is developed merging the two- ‘food’ and ‘nutrition’ strands
together from other sources and balancing it with the NCERT map. The
researcher’s concept map has connecting ideas from food and its components
on the left side and connections between the digestive, respiratory and
circulatory system on the right side (Figure 4.5). It has fewer concepts
compared to the concept map developed from NCERT text books. The relevant
concepts have a focus on food and human digestion only. The ramifications of
the topic into animal or plant nutrition or agricultural practices are omitted.
In the Indian context, at the primary level, contextual knowledge about food
eaten in different parts of the country is given importance in the food strand.
Further, children are introduced to ways of cooking, eating in the family, food of
animals and human beings, how food is grown and reaches us, spoiling of
foods, which are topics in the social context of children. In the nutrition strand,
digestion of food in mouth is introduced.
At the upper primary level, the strand of food and nutrition has been dealt in
detail. The sources of food derived from plants and animals, components of
food viz: carbohydrates, fats, proteins, vitamins, minerals, fibres and their
sources, balanced diet, deficiencies, crop production and spoiling of food by
micro-organisms. The strand nutrition includes human digestion and respiration
without going into details of biochemical breakdown of food by different
enzymes or physiological processes within different organs.
Textbooks by NCERT stress more about contextual knowledge on food &
nutrition as idealized by its policy of constructivism.
Concept statements about Food and Nutrition included in the derived concept
map developed by the researcher for elementary classes are as follows:
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Fig. 4.5: Derived Concept Map – Food and Nutrition (Developed by the Researcher)
• Our food is derived from various plant parts and animal sources.
• Food can be classified in several ways : food from plants and animals, food
from different parts of our country, junk food and nutritious food ,food for
animals and humans
• We have different types of teeth to chew, bite and cut food.
• Carbohydrates, Proteins, Fats, Vitamins and minerals are important
components of our food.
DIGESTION
FOOD AND
NUTRIENTS
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• Each component has an important role in providing energy, to build our
body and metabolism. Some food items are rich in one or more nutrients.
• Balanced diet provides us energy, maintains good health and provides
material for growth.
• An unbalanced diet may lead to deficiency diseases or obesity.
• Water though is not food, is required in the body for digestion and keep the
body hydrated.
• Fibres must be included in the diet for their role in healthy and efficient
digestion and bowel movement.
• Nutrition includes intake of food i.e ingestion, digestion, absorption,
assimilation and egestion.
• Digestion of food is a bio-chemical as well as mechanical process which
takes place in the different organs of the digestive system.
• Several glands are involved in the digestion of food. Food gets digested by
several enzymes secreted by those glands.
• Digested food is absorbed into the blood and circulated in the body cells
through circulatory system.
• The absorbed substances are used to build complex substances such as
proteins required by different parts of body, this is called assimilation.
• Digested food gives energy through respiration inside cells. Respiratory
system is involved in providing oxygen and removing carbon dioxide from
the body.
4.5. Students’ Conceptions of Food and Nutrition: Primary Source
In the first section, scientific perspective has been explored via the path
treaded by scientific community for over two thousand years during which the
content area of food and nutrition evolved. This exercise helped the
researcher to know the strands within the content area of food and nutrition. It
is imperative to know the conceptual resources present with the students for
whom the big ideas are meant. Pedagogical perspective of food and nutrition
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concepts was built by reviewing the research literature about students’
understanding of related concepts. The existing intended curricula in the
Indian and international context were analysed to comprehend the coverage
and depth of the ideas about food and nutrition meant for elementary
students. From this understanding, a concept map on food and nutrition was
developed (Figure 4.5) on the basis of which questionnaires were developed.
The purpose of this part of the study is:
• to identify the conceptual ideas of students in food and nutrition from class
4th to 8th
• to explore whether there is progression from contextual knowledge to more
scientific understanding
• to explore the trajectory of students from phenomenal to conceptual
understanding and macroscopic to microscopic understanding.
Tool Development
The outlines of the food and nutrition concepts were divided into 2 strands such
as (i) food and nutrients and (ii) digestion-system and process. Several
questions were framed on each strand keeping in mind the concept behind it
and the learning process in terms of identifying examples, differences,
definitions, meaning or finding relation etc. For example: Is water food for plants
and animals?
a. Yes, because water is taken in by plants and animals
b. Yes, because water is necessary for plants and animals
c. No, because liquids are not food for plants and animals
d. No, because water does not provide energy for plants and animals.
Relevant research studies were referred to search for appropriate assessment
items that could reflect students’ thinking. Some questions were derived from
few of research studies. These questions in the form of open-ended were
administered as pilot study and the final questionnaire has taken into
consideration the choices given in the research studies as well as the students’
choices. The questions thus formulated were ratified through expert opinion
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and placed in a questionnaire. These questions were piloted in a school with
around 40 students in each class from class 4th to 8th. The responses on this
set of questions were analyzed. The discrepancies in language were removed.
Minor modifications were made on the basis of whether or not the content of
the modules was comprehended by the students.
The sample for collecting data from primary source constitutes approx 200
students across each class from Class 4th to Class 8th from 5 schools of Delhi,
2 of which were Kendriya Vidyalayas and 3 were Public Schools of Delhi. The
purpose of choosing the Kendriya Vidyalayas was that they represent the
government set up with students from diverse socio-economic and linguistic
backgrounds. The 3 Public Schools cater to a similar clientele and also have
similar infrastructural and instructional facilities and all five schools were
affiliated to the CBSE & hence have similar curricular exposure.
Tool
The questionnaire on Food and Nutrition has 2 to 3 questions each on the
concepts of different food materials, nutrients in food, role of food in our
nutrition, digestive system and digestion. While younger students were asked
more about food materials and role of food in our body and digestion at a gross
level, older students were asked about role of nutrients in the body and role of
digestive organs in the body. There are overall 10 to 13 questions in the
questionnaire on food and nutrition for the students of the 3 stages. Refer to
Appendix A, B and C.
Analysis Design
The responses of students were analysed to see a general picture of
elementary learners’ conceptions about food and nutrition and difference
amongst stages from mean, standard deviation, and applying one way ANOVA
with 3 groups (stage 1, 2 and 3) and chi-square test of significance. Difference
within the stage that is between classes 4th and 5th and between 6th and 7th
were also tested for significance by chi-square test for all questions and also
between stages for select questions which were asked across stages.
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Percentage of responses, difficulty value of questions (hence concepts) were
analysed to see learners’ progression of concept within the sub-concepts.
Wherever students of different stages were presented with the same question,
data was presented through graphs and difference was tested for significance
by chi-square test and difference if any is indicated in the following section
where individual concepts are dealt.
4.5.1. General Analysis of Students’ Conceptions about Food and Nutrition
The central tendency through mean and distribution of scores (standard
deviation) were analysed to find the general understanding of students in food
and nutrition. The central tendency of a distribution is an estimate of the centre
of a distribution of values. The mean or average is the most commonly used
method of describing central tendency. To compute the mean all the values
were added up and divided by the number of students.
The mean of the students’ performance in the questionnaire on food and
nutrition and standard deviation across stages is as follows:
Table 4.2: Mean and S.D. across Stages
Food & Nutrition Stage-1 (N=401)
Stage-2 (N=360)
Stage-3 (N=196)
Mean 44.79 47.84 53.19
Standard Deviation 11.49 19.95 14.96
An observation of the mean shows that students of stage 3 performed better on
the test on the food and nutrition concept compared to the rest of the classes.
Older students understood better, i.e. stage 3 performed better than stage 2
and stage 2 performed better than stage 1 (Table 4.2).
One-way ANOVA was used with the three groups of students, stage 1, stage 2
and stage 3 to investigate statistical differences among them. The statistical
results were interpreted only if the data met a basic assumption for the use of
ANOVA, i.e. the variances of three groups were similar (homogeneity of
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variance). The quantitative data results indicate there are statistically significant
differences among three groups on their performances in the food and nutrition,
F (2, 954) =18.55, p< 0.05.The stage 3 (N = 196, Mean = 53.19, S.D. = 14.97)
outperformed the stage 2 (N=360, Mean=47.84, S.D=19.96) and stage 1 (N =
401, Mean = 44.79, S.D = 11.49). There is no significant difference between the
stage 2 and stage 1 on their performance (Refer to Appendix D).
The data indicate that as students progress through the science curriculum
from primary to middle level, there is a progression in their knowledge about
food and nutrition.Stage1 had studied more about food than about nutrition,
stage 2 had both the concepts; stage 3 did not study much about both
concepts. Cognitive maturity of stage 3 appears to shift their understanding
about food and nutrition towards progression. A bigger sample with a full range
of questions on food and nutrition may help to make more definitive
conclusions.
Since the purpose of present research is to find the concepts which are
conceptualized by learners easily or with difficulty, a simple difficulty value was
computed. The concepts with 0 to 0.40 difficulty values (D.V.) were considered
difficult, concepts with 0.41 to 0.60 D.V. were considered as having average
difficulty, and concepts tested with 0.61 D.V. to less than 1 were considered
easy. The questions asked were not instruction/curriculum based; hence a
large value (of 0 to 0.4 or 0.61 to 1) was allocated to difficult or easy concepts
not to lose any valuable data (refer to Appendix G).
Table 4.3 presents the difficulty continuum of food and nutrition concepts
across the 3 stages. It is found that concepts found difficult in stage1 seemed to
be easy for stage 2 and so on. Students of all the 3 stages found concepts
related to food easy. Concepts related to food and related to students’
experience like seeds, meat, ghee were conceptualized by students of all 3
stages & were easy for all. Concepts related to transformation of food inside
digestive system and assimilation in the body was found difficult by all.
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Table 4.3: The Difficulty Continuum of Food and Nutrition Concepts across Stage 1, 2 & 3
D.V. Stage 1 Stage 2 Stage 3
Easy (0.61 to < 1) concepts
- Seeds as food
- Meat as food
-Role of food in the body
- Ghee has nutrients such as fats
- Energy is required to digest food.
- Glucose as food
- Role of food in the body
- Eggs as food items made up of cells
- Chemical breakdown by juices from glands
- Function of stomach
- Sequence of digestion
Average 0.60 –0.41
- Glucose as food
- Milk as a wholesome food
- Calcium is present in bones
- Digestion starts in mouth
- Function of stomach
- Pulses and eggs are body building foods
- Chemical breakdown of food by juices from glands
- Micronutrient requirement in body
- Digestion is complete in small intestines
- Meaning of digestion
Difficult 0.44-0.0
- Insects as food
- Flowers as food
- Pulses and eggs are body building foods
- Role of nutrients in body(only carbos)
- Identification of minerals
- Digestion is complete in small intestines
- Identification of nutrients in given diet
- Absorption of food from digestive system
- Identification of minerals
- Digestion is complete in small intestines
- Body structures grow from rearrangement of particles of food
From this study of students’ conception about food and nutrition from age 9 to
13, it was found that students of stage1 find many concepts (as many as 6
concepts) difficult. Five of these concepts are related to nutrients in food and
one is related to digestion. They found the conceptualisation of role of nutrients
in the body difficult to understand. They also could not conceptualise about the
process of digestion though they understood how digestion starts in mouth.
They found classifying food items which they are familiar with like meat and
seeds easy, but found identification of insects and flowers difficult.
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Similarly if the conceptualisations of students of stage 2 (11 and 12 years) are
considered, they found four concepts difficult. Their conceptualisation about
digestion, role of various organs or sequence is better than the students of 9 or
10years. They could not identify nutrients in food items which shows their lack
of content knowledge about nutrients and hence balanced diet also. Chemical
transformation process takes place with the help of glands is conceptualised by
many, but the absorption and assimilation is not understood by most students.
The students of 13 years of age have conceptualised most concepts related to
food and nutrition inquired of them. They did not find most concepts difficult
except one concept on the assimilation of food and growth. Conceptualisation
of it will require understanding of particulate nature of matter and conservation
of matter (Leeds National Curriculum Science Support Project, 1992).
The possibility of progression of elementary learners within sub-concepts is
analysed and interpreted comprehensively in the following section.
4.5.2. Comprehensive Analysis of Students’ Conceptions about Food and
Nutrition
The development of understanding about food and nutrition involves
understanding many aspects of it such as different food materials, nutrients in
food, role of food in our nutrition, digestive system and digestion. In this section,
it will be investigated if the concept sequence within food and nutrition is
supported by student responses to items addressing the above aspects.
An analysis was done to find percentage of responses of each concept asked.
Students’ responses were analysed to find whether they corresponded to
scientific conceptions or alternative conceptions.
Scientific Conception – The term ‘scientific conceptions’ refers to those ideas
about a particular concept or subject that are presently shared by the scientist
community. The use of the term ‘scientific conception’ instead of the ‘correct’
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conception is depictive of the dynamic nature of science and allows scope for
the possibility of revision of scientific knowledge which is how the disciplinary
knowledge develops.
Alternative Conception – The term ‘alternative conceptions’ in this study refers
to all ideas which differ significantly from the accepted scientific view (Gilbert,
1983). In the present study the term ‘alternative conceptions’ may include within
its purview:
- Pre-conceptions that have survived formal instruction.
- Hybrid conception resulting from the interplay between formal and pre
conceptions. These may not be entirely incorrect ideas but may incorporate
some correct ideas as well.
- Limited conceptions.
An analysis was done to find percentage of responses for each concept asked.
Chi-square test of significance for all questions on food and nutrition between
classes 4th and 5th reveals that all 15 questions except 2 questions showed no
significant differences. Those 2 questions have been indicated for the
difference in the following section. The chi-square test shows that classes 4th
and 5th are more homogeneous and it is logical to include them in one stage,
i.e. stage 1.
Chi-square test of significance for all questions on food and nutrition between
classes 6th and 7th reveals that all 11 questions except 3 questions showed no
significant differences. Those 3 questions have been indicated for the
difference in the following section. The chi-square test shows that classes 6th
and 7th are more homogeneous and it is logical to include them in one stage,
i.e. stage 2.
On the basis of their responses, students’ conception about food and nutrition
was summarised as follows.
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4.5.2.1. Students’ Conceptions about Food and Nutrients
There are 7 questions for students of stage1 (class 4th and 5th) and 5
questions for students of stage 2 (class 6th and 7th) on strand ‘Food’ in the
questionnaire and there are 3 questions in the questionnaire meant for students
of stage 3 (class 8th) on the same topic (Refer Appendix A, B and C). Since
younger students have more exposure about food they were asked more
questions on it. The questions were related to their understanding of what is
food and what is not, identification of nutrients, role of nutrients in the body. The
students’ conception about water as food, role of nutrients, identification of
minerals in food, has been traced from stage1 and 2 (classes 4th to 7th). The
understanding of glucose as food and role of food in the body has been traced
from stage 1 to stage3. The first half of the questionnaire was on food and its
nutrients and the concepts of elementary students on food were found to be
very similar to the findings mentioned in the research studies quoted below.
Hart K.H., Bishop J.A. and Truby H. (2002) employed a qualitative method and
114 children aged 7-11 years across age, gender and socio-economic status
(SES) were the sample. Across the groups, restrictive food rules were reported
and gender and SES difference were apparent in relation to parental control
over food and children’s nutritional knowledge. The limitation of the children’s
cognitive development was seen in their conceptualization of food groups, and
in the lack of understanding in their food-health or food – nutrient association.
Francis R. and Hill D. (1993) investigated the concepts held about food and
nutrition by students in grade 4, 8 student-teachers and parents of grade 4
students. They found that for many concepts relating to food selection, the
basic ideas were consistent among the groups despite the influence of formal
education. In particular, misconception about energy and its role in nutrition and
particular food groups was an important finding.
Sheila A. Turner (1997) conducted an action research project involving primary
teachers on in-service teacher education program in London. The research
aimed to investigate children’s knowledge and understanding about food and
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diet. Teachers interviewed children aged from 5 to 12 years. Pictures of food
were used to identify how children choose food to eat and how they classify
foods, and to explore their understanding of nutrients. The findings suggested
that even five year olds have some understanding of relationship between food
and heath. Children also held alternative ideas about food, especially about the
function of food and the importance of specific nutrients.
Tables 4.4 to 4.16 present elementary students’ conceptions about food.
Table 4.4: Food and Non-food
Concept
Stage 1
Class IV & V Age 9 to 10, N=401
Scientific Concept Alternative Concepts
Insects as food 8.2% 91.8% think insects are not food
Seeds as food 65%* 35% think seeds are not food
Meat as food 89% 11% think meat is not food
Flowers are food 12% think it is food 88% think this not food
* Significant difference detected: Chi-square statistic=9.36, df =1, p<0.05.
Students of stage 1 (ages 9 to 10) were asked to classify six types of food
items like meat, seeds, insects, flowers, glucose and water into two categories
of whether they are food or not. Their classification about water and glucose is
presented in tables 4.5 and 4.6.
Around 65% of stage 1 (58% of class 4th and 72% class 5th) conceptualised
seeds as food; rest of the students could not understand seed grains being our
mainstay in food. Around 89% understood meat being food. Most students had
difficulty understanding that insects and flowers can be food of either humans
or animals (Table 4.4). Though the topic is part of primary text books in Class
3rd, many did not think that people might be eating flowers or insects. They had
human centric view point, did not consider animal nutrition at all. This is similar
to the findings of Lee, Y.J. and Diong C H, (1999) that even secondary
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students’ (age 16-18 years) understandings of the biological concepts of food
were anthropocentric and not applied across living organisms in heterotrophs or
autotrophs as a whole. Simpson and Arnold (1985) surveyed children from
aged 11 to age 15, and suggested that many children associated ‘food’ only
with substance that they can identify as being edible. In younger children this
includes culturally appropriate human foods, whereas in older children it is
extended to examples from wider cultures and other organisms.
Table 4.5: Water as Non-food
Concept
Stage 1 Stage 2
Class IV & V
Age 9 to 10, N=401
Class VI & VII
Age 11 to 12, N=360
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Water as food Above 60% accept water as food Above 73% accept water as food.
In the classification task, 60% of stage1students thought water to be food. Above
70% students of stage2 consider water to be food because water is necessary
for plants and animals. Text books present water as a component of food while
some nutrition specialists consider that organic substances only can be food. Lee
Y.J. and Diong C.H. (1999) too have reported in their study that many students
confused the concept of nutrients and water, believing water to be food.
Research on Nutrition by Project 2061(American Association for Advancement of
Science, AAAS, 1993) report that lower elementary school children may believe
that food and water have equivalent nutritional consequences.
Table 4.6: Glucose as Food
Concept
Stage 1 Stage 3
Class IV & V
Age 9 to 10, N=401
Class VIII Age 13, N=196
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Glucose as food 56% Not food 44% 68% Not food 32%
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While 56% stage1 think that glucose is food in the classification task, 68% of
stage3 students think that glucose is food (Table 4.6). The context given for
stage3 students is glucose administered intravenously to a patient. For around
15% of older students, glucose is not food and 12% remain unsure whether
glucose is food or not. These 27% students may be considering anything taken
orally to be food and not intravenously.
Fig. 4.6: Glucose as Food
Table 4.7: Role of Nutrients in the Body
Concept
Stage 1 Stage 2
Class IV & V
Age 9 to 10, N=401
Class VI & VII
Age 11 to 12, N=360
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Pulses, eggs are ________ foods
Body building 28%
Energy giving 51% Others 21%
Body building 57.5%*
Energy giving 26% Others 16.5%
* Significant difference detected: Chi-square statistic = 11.54, df =4, p<0.05
Protein-rich food items like pulses etc. were identified as body-building food by
57.5% of stage2 (50% of class 6th and to 65% students of 7th), but 26% think
56 56
68
0
10
20
30
40
50
60
70
80
Class IV Class V Class VIII
Pe
ren
tag
e
Glucose as food
113
that they are energy giving foods. Correct response increased in class 7th by
15% and incorrect response decreased. Influence of curriculum was seen in
class 7th, though topic is introduced in class 6th. Only 28% of stage1 identified
pulses etc as body-building food, but 51% of stage1students think that they are
energy giving foods. Lucas A. (1987) had found in his survey of 1033 adults
that they were familiar with the names of dietary components but not with their
functions: 37% thought that proteins provide most of energy needs of human
body and 19% thought vitamins do. He also found that proteins are more
frequently identified with food by 1045 students of ages 10-19: most of this
sample selected proteins as product of photosynthesis, presumably relating
proteins to food.
Table 4.8: Role of Food in the Body
Concept
Stage 1 Stage 3
Class IV & V Age 9 to 10,
N=401 Class VIII
Age 13, N=196
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Role of food in the body
88.3% 11% Why we eat food
54% to get energy
20% think we eat to allow the body to function
9.2% for tissue growth & repair
On the concept, role of food in the body, stage 1 students were logical in opting
for many roles of food for growth, energy and good health (Table 4.8). Sheila A.
Turner, (1997) investigated children’s (aged from 5 to 12 years) knowledge and
understanding about food and diet. Pictures of food were used to identify how
children choose food to eat and how they classify foods, and to explore their
understanding of nutrients. The findings suggest that even five year olds have
some understanding of relationship between food and health though they hold
114
alternative ideas about food, especially about the function of food and the
importance of specific nutrients.
A slightly different question was asked to stage-3 students on why we eat food.
About 54% of the students think that we eat food to give energy; 20.4%
students think that food allows the body to function. Leach J., Driver R., Scott P.
and Wood R.C. (1992) studied progression in understanding of concepts of
food and energy as part of ecology concepts in students of 5 to 16 years. They
found that younger children of 5 to 7 years (Key stage1) do not attribute any
physiological function to food and think that food is a source of energy rather
than of matter for growth and that matter for growth may come from within the
body/seed. Slightly older children of 7 to 11 years (Key stage 2) think the same
about food and energy except that they develop little more knowledge about
food matter turning into body matter. Students of ages 11 to 14(Key stage 3)
have little knowledge of food matter being transformed to body matter and they
have the idea that plants get food from soil. Students of 14 to 16 years (Key
stage 4) have the idea that food is a scarce resource in ecosystems and that
plants get food from soil. They too have little knowledge about food matter
being transformed to body matter. They rarely distinguish food, matter and
energy.
Table 4.9: Role of Nutrients in the Body
Stage-1 Class IV and V Age 9-10 years, N=401
Concepts Scientific Concept Alternative Concepts
If we eat only rice for a month, what happens __________
Falls ill with deficiency 32% People will grow fat 36%
People will grow thin 32%
Students of stage-1 when asked to answer what happens if one eats only rice
for a month, almost equal number of students thought they would grow fat or
thin or would fall ill with deficiency (Table 4.9). Students do not attribute any
particular role to a group of food like carbohydrates, so they are equally divided
between all possibilities. Inagaki and Hatano (1987) report from their research
115
on young children that almost all the children of 4-5 years recognized that
weight change is caused by food intake rather than intention or desire. Lee and
Diong (1999) asked similar question to 66 students of age (16-18 years)
Singapore qualitatively and found that 78% answered scientifically and 11%
each thought that eating carbohydrates would make them either fat or thin.
Older students seem to understand this concept scientifically.
Table 4.10: Identification of Minerals
Concept
Stage 1 Stage 2
Class IV & V
Age 9 to 10, N=401
Class VI & VII
Age 11 to 12, N=360
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Calcium, Iron are examples of __________
Minerals 28% Vitamins 57.4%
Carbohydrates 12.5% Minerals 41%
Vitamins 50% Carbohydrates 9%
Only 41% students of stage 2 have the concept that Calcium, iron etc. as
minerals. Students of stage 1 identify Calcium, iron as minerals with difficulty. A
small percentage thinks that they are carbohydrates, but majority of them think
that Calcium etc are vitamins. There seems slight increase identifying minerals
from stage 1 to stage 2 (Table 4.10). So the concept is not clear to most.
Students of class 6th are taught about minerals as components of food.
Table 4.11: Nutrients in Milk – Stage 1
Concept
Stage 1, N = 401
Class IV & V Age 9 to 10
Scientific Concept Alternative Concepts
Milk is wholesome food, because it has _______, _____, _____
Vitamins, minerals sugar & proteins 57.6%
Because milk has proteins 40%
116
Students of stage 2 tick the component of food which they think are present in
milk (Table 4.11).
Table 4.12: Nutrients in Milk – Stage 2
Stage 2 Class VI & VII
Around 30% know that milk has fats 20% have the concept of carbohydrates in milk
Little more than 60% recognize ‘proteins’ and ‘minerals’ as nutrients and identify proteins and vitamins to be present in milk
32% have the concept of minerals present in milk
On being asked why milk was considered a wholesome food, stage-1 students
marked many nutrients against milk. They know that milk contains important
nutrients, but whether it has many nutrients, they are not aware. Students of
this stage do not understand that milk has fats. Around 30% students of stage 2
know that milk has fat. Less percentage of students selecting carbohydrates in
milk shows that most students of stage 2 do not understand that the milk has
carbohydrates in the form of lactose (Table 4.12).
Table 4.13: Nutrients in Protein Rich Food- i.e. Chana and Ghee
Concept
Stage 2, N=360
Class VI & VII Age 11 to 12
Scientific Concept Alternative Concepts
Nutrients present in chana are Proteins 44% -
Nutrients present in ghee are 90% Around 20% have the concept that ghee has all nutrients
Only 44% students of stage 2 understand that chana (black gram) has proteins.
More than 90% correctly identify fats with ghee. The response of students to
questions on identifying nutrients present in some common food items showed
that students were familiar with the names of dietary components but were not
familiar with the type of food items which have them. Research by Brinkman and
Turner (1991) suggests teaching did not change certain ideas of Dutch and
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English teenagers about fat in the diet. A small number of students (about 10%)
think that it is not necessary for your health to eat fat. Fat tends to be associated
with unhealthy food. Dixey R, Sahota P, Atwal S and Turner A (2001), presented
data from focus groups with 300 children (aged 9-11) in 10 schools in Leeds,
UK. Analysis of the frame scripts shows that children understood the
relationship between their diet and health, both present and future. Fat played a
predominant role, with a healthy diet being one that did not contain too much fat.
To the contrary, the common alternate conception about ghee in 20% of our
students was that fats have all nutrients, suggesting that it is healthy to eat ghee
according to them. Similar findings on misconceptions about several nutrients in
adults were concluded by Lucas (1987) also referred to after table 4.7.
Table 4.14: Element Present in Bones
Concept
Stage 1
Class IV & V Age 9 to 10, N=401
Scientific Concept Alternative Concepts
Element present in bones is ___________ Calcium* 61% Iron 30%
Proteins 9%
* Significant difference detected: Chi-square statistic=18.99, df =3, p<0.05
About 61% of stage 1 (53% of class 4th and 69% of class 5th) identify the
element present in bones as calcium (Table 4.14). The topic is not part of their
syllabus, but because of exposure to advertisements about various health
foods containing calcium through mass media, students know that calcium is
present in bones.
Table 4.15: Components in Balanced Diet
Concept
Stage 2
Class VI & VII Age 11 to 12, N=360
Scientific Concept Alternative Concepts
What is missing in the diet consisting Roti, vegetables &
potatoes Proteins 36%
Fibre 45% Carbohydrates 19%
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A question meant for students of stage 2 was on balanced diet. Students had to
identify what is missing in a combination of food items in Nina’s diet in which
food with proteins are not present (Table 4.15). Students do not know about
components of food, so around 36% only identified proteins. Around 45% think
fibres are missing from her food, while fibres are present in the given
combination in the form of roti and vegetables, so maximum students do not
identify fibre either. In the correct response, maximum contribution is of high
achievers, so it is not guess work by low achievers either. S.A. Turner (1997)
too found the lack of knowledge about fibres in primary children which she
reported was a cause of concern.
Table 4.16: Food made up of Cells
Concept
Stage 3
Class VIII Age 13, N=196
Scientific Concept Alternative Concepts
___________ is the food item made up of cells
Eggs 93% Oils 4%
Students of stage-3 had to identify food items made up of cells. About 93%
have the concept that eggs are made up of cells (Table 4.16).
Arnold (1983) and Simpson (1983) investigated on 249 14-15 year-old Biology
students in six British schools, who had all been taught about food and
digestion. Three quarters of the pupils accept that carbohydrates and proteins
are made of molecules but a large minority thought that they are also made of
cells.
Table 4.17: Quantity of Micro-nutrients
Concept
Stage 3
Class VIII Age 13, N=196
Scientific Concept Alternative Concepts
Vitamins and minerals are measured in ________ units
Milligrams 51% Grams 34%
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Half of stage 3 has the concept that micro nutrients are required in milligrams,
but 34% also think that they are required in grams. Only calcium may be
required in grams (Table 4.17).
The conceptions of elementary students on food were found to be very similar
to the findings mentioned in the research studies by K.H. Hart, J.A. Bishop, H.
Truby (2002), Francis R and Hill D (1993) and Sheila A. Turner (1997).
4.5.2.2. Students’ Conceptions about Digestion
There are 3 questions in the questionnaire meant for students of stage1, 4
questions in the questionnaire for students of stage2 and 7 questions meant
for students of stage3 on digestion. The questions were related to their
understanding of meaning of digestion, the process of digestion, role of
different organs and glands in the body. Students’ conception about role of
stomach in digestion has been traced from stage 1 to stage3. The students’
understanding about role of gastric juices in the process of breakdown of food
has been traced from stage 2 and 3. The conception of students’ about
completion of breakdown process of food in the body has been traced from
stage 1 to stage 3. Tables 4.18 to 4.26 present elementary students’
conceptions about digestion.
Children are supposed to have some knowledge about digestion from age four.
Reiss and Tunnicliffe (2001) in their study of drawings of organs and organ
systems of human body of students from 5 to 20 years also found that the most
well-known systems are digestive systems and the respiratory system. Susana
Gracia-Barros and others (2011) investigated 342 Spanish young children’s
(aged 4 to 7) evolution of knowledge about the digestive system and respiratory
system of the human beings and of other animals before they studied about
them at school by means of drawings made by children. They found that the
children recognized specific organs in their own bodies which they associated
with the intake of food and air and they usually extrapolated those organs to
other animals they were familiar with. Their ideas about the digestive system
were more adequate than the ones about the respiratory system. Their ideas
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improved as they become older, above all those concerning the digestive
system.
There are disagreements among researchers about the origin of the biological
domain in children. Carey (1985) claimed that the biological domain emerges
from the psychological domain. Keil (1992, 1994) stated that young children’s
initial biological theory is an independent and autonomous domain from
childhood. Hatano and Inagaki (1997) noted that biological knowledge is
constructed from inferences drawn from daily experience; hence it is application
of empirical knowledge to related contexts. If children possess biological
knowledge as an autonomous domain, then instruction in biology should be
effective. This effectiveness depends on the ability of the teacher to enhance
restructuring of their biological knowledge through enrichment and conceptual
change.
Table 4.18: Digestion of Food in Mouth
Concept
Stage 1
Class IV & V Age 9 to 10, N=401
Scientific Concept Alternative Concepts
Digestion of food starts in ________ Mouth 54% Stomach 30%
Students of stage1 were asked about where the digestion process starts.
Around 54% have the scientific concept that digestion starts in mouth. About
30%students have the concept that digestion of food begins at stomach. The
topic has been dealt with in class 5th, but there was no difference in the
understanding of students of class 4th and 5th. Yilmaz Cakici, (2005) has
reported in his study of 283 Turkish children's understanding of digestion in
Grades 4 and 5 (ages 10-11) through the use of an open-ended questionnaire
and follow-up interviews. In his study, even after teaching the unit on digestion,
only 20.4% children of class 4th and 34.9% of class 5th answered correctly that
digestion starts in mouth, more than 50% in class 4 and 47% in class 5th
answered that it started in stomach. Correct conceptions were more in the
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interviews. In the present study, higher number (54%) of students of the same
age has the scientific concept
Table 4.19: Chemical Breakdown of Food
Concept
Stage 2 STAGE3
Class VI & VII Age 11 to 12,
N=360 Class VIII
Age-13, N=196
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
__________ helps in chemical breakdown of food.
Juices from glands 52.4%*
Organs 17%, Water 11%, Hajmola 9%
Juices from glands 80%
Organs 8%, Water 4%,
Hajmola 6%
* Significant difference detected: Chi-square statistic=24.88, d f =4, p<0.05
Fig. 4.7: Gastric Juices in Digestion of Food
Students of stage 2 and 3 were asked about their conception on what helps in
the chemical breakdown of food in the digestive organs. About 52.4% of stage
2 (40% of class 6th and 65% students of Class 7th) understand that digestive
glands help in chemical break down of food in the digestive organs, 80% of
stage 3 students have the scientific concept (Table4.19). There is an increase
of 25% in recognition of digestive glands as helping in chemical breakdown of
food from class 6th to 7th and 40% increase in recognition by class 8th from
Class VI Class VII Class VIII
Digestion of Food 40 65 80
0
10
20
30
40
50
60
70
80
90
Pe
rce
nta
ge
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class 6th (Fig 4.7). Around 17% of students of 6th class select responses which
reflect misconception like hajmola and spices helping in chemical break down
of food. The topic on Digestion of food is dealt in the class 5th and 7th in detail.
Still majority of students of stage 1 and 2 did not have the scientific conception.
This is similar to Cakici (2005)’s finding about younger students of class 4th
and 5th; around 40% of class 4th and 56% of class 5th students had the
scientific idea that digestive juices in glands help in breakdown of food in
digestion while 38% of fourth graders and 27% of fifth graders also thought that
breakdown was because of water, acidic drinks, green plants or oils etc.
Table 4.20: Function of Stomach
Concept
Stage 1 Stage 3
Class IV & V Age 9 to 10, N=401 Class VIII Age 13, N=196
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Function of stomach is ________
Digesting 61% Storing food 23.5%
Filtering 9% Digesting 76%
Storing food 20% Filtering 2.6%
Fig. 4.8: Role of Stomach in the Body
51
71 76
30
172012.4
4.72.6
0
20
40
60
80
100
120
Class IV Class V Class VIII
Digesting Storing Filtering
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Students of stage 1 and 3 were put the question about the function of
stomach. Around 51% of the class 4th students understand that the function
of stomach is digesting, but 30% also think that storing is a function of the
stomach. An additional 12.4%thinks that stomachs filter food. There is an
increase of 20% in the correct response of class 5th, because the topic was
dealt in class 5th itself. Around 17% of class 5th students think that stomach
stores food, only 4.7% think that stomach filters food (Fig. 4.8). Their
responses are very similar to the conceptions of medieval physiologists
like Galen who wrote that stomach performed a filtering or storing role.
In Cakici (2005)’s study too, some children considered digestion to be a
filtering process that is performed by the stomach in order to separate the
useful and waste parts of food. These views 'melting of foods' and 'filtering of
foods' had not been mentioned in the literature previously than Cakici. On
being asked the same question, about 76% of class 8th understand that
function of stomach is digesting; still 20% have the misconception that it
stores food. This misconception seems to persist from stage1; however the
alternate concept of filtering role decreases considerably (Table 4.20).
Table 4.21: Digestion is Complete in Intestines
Concept
Stage 1 Stage 2 Stage 3
Class IV & V
Age 9 to 10 Class
VI & VII Age 11 to 12 Class VIII Age 13
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Scientific Concept
Alternative Concepts
Digestion (break down) of food finishes at ________
Small intestines 10.5%
Anus 49% Large intestine 24%
Small intestines 20.3%
Anus 40% Large intestine 24%
Small intestines 59%
Anus 26% Stomach 9.4% Large intestine 4.6%
On being asked where digestion (break down) of food finishes, around 49% of
students of stage 1 think that digestion (break down) of food finishes in anus.
Only 10.5% students of stage1 have the scientific conception that digestion of
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food finishes in small intestines. As in the case of stage 1 students, more than
75% of students of stage-2 do not understand where the digestion process
finishes. Only 20% of stage-2 students know that it finishes in small intestines.
About 24% think it is at large intestines. About 40% think digestion finishes in
anus. Around 60% of stage 3 students understand that digestion of food
finishes in small intestine and not at other organs. About 10% think that
digestion finishes at stomach. But still 26% of stage3 students think that
digestion finishes at anus (Table 4.21 and Fig. 4.9). Cakici (2005) had found a
lower percentage of correct conception in students of class 4th and 5th at 3.4%
and 7.2% respectively, while lower percentage of students at 18% of class 4th
and 13% of class 5th students had the conception that digestion finishes at
anus. This is probably because of number of distracters provided by him were
more than eight. Teixeira F.M. (2000), researched children’s conceptions of the
structure and function of the human digestive system based on data from an
investigation carried out with 45 children between the ages of four and ten. The
results indicate that the concept of transformation of food can constitute an
obstacle to comprehension of the scientific model of the functions of the
digestive system for children aged up to ten.
Fig. 4.9: Digestion gets completed in Small Intestines
0
10
20
30
40
50
60
70
Class IV Class V Class VI Class VII Class VIII
Digestion of food finishes
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Table 4.22: Absorption of Digested Substances
Concept
Stage 2
Class VI & VII Age 11 to 12 N=360
Scientific Concept Alternative Concepts
Digested substance go to ___________
Absorption takes place 32% Digestion is complete in stomach & pass to intestine 48% Remain in stomach 10%
About 48% of the students of stage2 think that complete digestion takes place in
stomach and then digested substances go to small intestines. Only 32% has the
scientific concept that digested substances are absorbed by blood from
intestines (Table 4.22). This notion mentioned above affects their understanding
about destination of substances obtained by digestion.
Table 4.23: Meaning of Digestion
Concept
Stage 3
Class VIII Age 13, N=196
Scientific Concept Alternative Concepts
Digestion of food is ________
Breaking down of food in stomach and small intestines and food entering into body 54.6%
Passage of food down organs 22% Role of stomach in digestion 11% Role of stomach in filtering 11%
Around 55% of stage 3 students correctly understand the process of digestion
of food; still 22% think it is simply movement or passage of food through mouth
to different organs before getting excreted through anus. Another 22% too
understand the process as filtering or breaking down of food. Cakici (2005)
reported that the most significant finding was around 30% of 4th and 20% of 5th
graders’ conception of the digestive process as 'melting of foods' rather than
'breaking foods down' and that there was an increase in the proportion in
children who considered breaking down of food in class 5th rather than melting,
but the difference was not significant.
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Table 4.24: Sequence of Process of Digestion
Concepts
Stage 3 Class VIII, N=196
Scientific Concept Alternative Concepts
The sequence of process of digestion is
Ingestion, breaking into simple substance,absorption, assimilation and egestion 65%
Breaking of simple substances 15% Perceive that absorption takes place first 14%
Similarly 65% of stage 3 identify the sequence of process of digestion correctly,
14% to 15% pick incorrect sequence thinking absorption or digestion takes
place earlier than ingestion or eating (Table 4.24).
Simpson (1984) found that at thirteen, children’s ideas of the sequences of
digestion are very confused, both in terms of the anatomical route and the
processes. Routes may include the trachea, heart, kidneys in some children’s
minds. The sequence of processes may start with breaking into soluble
particles, releasing energy, followed by swallowing.
Table 4.25: Energy Needed for Digestion
Concept
Stage 2
Class VI & VII Age 11 to 12, N=360
Scientific Concept Alternative Concepts
Is energy needed to digest the food we eat?
Yes 61% No 22%
Unsure 14%
Students of stage2 were asked if any energy is spent on digesting food.
Though only 50% of the students of class 6th understand that our digestive
system requires energy to digest the food we eat, 73% of class 7th understand
it correctly. This concept is the basis of understanding energy need for all the
body functions (Table 4.25).
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Table 4.26: Food and Growth
Concept
Stage 3
Class-VIII Age 13, N=196
Scientific Concept Alternative Concepts
If we do not eat for 2/3 days what will happens in our blood?
Fewer nutrients in blood 67%
No nutrients 18% No change in amount of nutrients 11%
Our body structures grow as __________
Particles from food (atoms) are rearranged to form particles of body structure 28%
Food accumulates inside body 38% Vitamins and minerals are added to the body unchanged 24%
While 67% of stage 3 students think that on fasting for 2-3 days there will be
fewer nutrients in the blood, 18% think that there will be no nutrients in the
blood. While 85% (67+18) seem to understand the relation between food and
nutrients, 11% do not understand it and 18% do not foresee any storage
mechanism for nutrients in the body.
To the second question shown in the table 4.26, only 28% think that particles
from food are rearranged in body, 38% think that food accumulates inside the
body and 24% think that vitamins and minerals are added to the body
unchanged. This finding is similar to the finding by Smith and Anderson, 1985
and Leach et al 1992 under CLIS project .They found that some students of all
ages think food is a requirement for growth, rather than a source of matter for
growth. They have little knowledge about food being transformed and made
part of a growing organism’s body. Francisco Nunez and Enrique Banet, (1997)
similarly described the conceptual patterns concerning human nutrition
encountered in a sample of 444 students aged between 11 and 17. They found
that only 69% of students of ages 16-17(who had studied biology) understood
the relation between cellular respiration and digestion and that digestion
converts complex nutrients into simple substances. The absence of an
association between digestion and circulation was a didactical obstacle (no
drawing with the passage of digested food into the blood in the school
textbooks) and an epistemological obstacle was the absence of understanding
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of the digestion of solid food and the permeability of the intestinal wall for the
passage of digested food into the blood was indicated by Carvalho (2004) in
her cross-sectional study of Portuguese primary school pupils.
4.5.3. Discussion
The following table gives the overall summary of the analysis from the primary
source.
Table 4.27: Scientific and Alternative Concepts across Stages
Stage 1 Scientific Concept Alternative Concepts
Food and Nutrients
Insects may be food Insects are not food
Seeds are food Seeds are not food
Flowers may be food Flowers are not food
Water is not food Water is food
Glucose is food Glucose is not food
Pulses and eggs are body building foods
Pulses and eggs are energy giving foods
Food has many roles growth, energy and good health
Food has few roles in the body
If we eat rice only we will fall ill with deficiency
If we eat rice only we may grow fat
Calcium and Irons are Minerals Calcium and Irons are Vitamins
Milk is wholesome food because it has minerals, vitamins, sugar and proteins
Milk is wholesome food because it has proteins
Element present in bones are Calcium Element present in bones are iron
Digestion
Digestion of food starts in Mouth Digestion of food starts in Stomach
Function of stomach is digestion Function of stomach is storing
Digestion break down of food finishes at small intestine
Digestion break down of food finishes at anus
Stage 2 Scientific Concept Alternative Concepts
Food and Nutrients
Nutrients present in Chana are proteins
Nutrients present in Ghee are fats Ghee has all nutrients
Water is not food Water is food
Pulses and eggs are body building foods
pluses and eggs are energy giving foods
Calcium and Irons are Minerals Calcium and Irons are Vitamins
proteins are missing diet consisting of Roti, Potatoes and vegetables
Fibers are missing
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Digestion
Juices from glands helps in chemical breakdown of food
Digestive organs, water, hajmola
helps in the chemical breakdown of the food
Digestion of food fines at the small intestines
Digestion of food finishes at anus
Digested substances are absorbed Digestion is complete in stomach and passed to intestines
Energy is needed to digest the food Energy is not required for the digestion
Function of Stomach is digesting the food
Function of stomach is storing
Stage 3 Scientific Concept Alternative Concepts
Food and Nutrients
Glucose is food Glucose is not food
Eggs are made up of cells Oils are made up of cells
Vitamins and Minerals are measured in Milligrams
Vitamins and Minerals are measured in Grams
Digestion
Juices from glands helps in chemical breakdown of food
Digestive organs, water, hajmola helps in the chemical breakdown of the food
Function of Stomach is digesting the food
Function of stomach is storing
Digestion of food finishes at the small intestines
Digestion of food finishes at anus
Digestion of food is breaking down of food in the stomach and small intestines and food entering the body
Digestion of food is the passage of food down the organs.
Sequence of the process of digestion is ingestion, breaking in to simple substances, absorption, assimilation and egestion
Breaking of simple substances
If are not consuming the food for three or four days there will be lesser nutrients in the blood
There will be no nutrients
Our body structures grow as particles from food are rearranged to form particles of body structure
Food accumulates inside the body.
From the primary data, one may generalise that students of higher class i e
older students understand concepts of food and nutrition better than younger
students; students’ understanding of concepts did improve in class 8th. Though
most of the food and nutrition concepts were part of science teaching at classes
6th and 7th, students of class 8th seemed to have understood them better than
classes 6th and 7th.
130
Understanding about food and nutrition concepts can be generalised only about
the items asked. Different patterns may emerge if other sub-concepts are
included in the items.The generalisations about findings in this study are
limited, since sample came from five schools that served diverse school
populations in terms of language, socio-economic status and achievement.
Tracing the trajectory of evolution of science concepts among elementary
students is challenging. Fundamental ideas tend to be abstract and
parsimonious, their appropriateness and usefulness cannot be appreciated by
students without the conceptual resources or epistemological commitment of
the practising scientific community. Owing to developmental and experiential
constraints of students, some of the food and nutrition concepts may be difficult
for students to understand. The constraints could be imposed by limitations
placed by curriculum.
Students of both classes within stage1 conceptualised about nutrients in food
and digestion in a similar way. Students of class 5th had their exposure to the
topic on digestion in curriculum, but it seemed to have marginal effect on them.
However, they understand the role of mouth and stomach better than class 4th
students. Teixeira (2000) found from his study of children’s conceptions about
digestion from age 4 to 10 that by the age of ten the function of the digestive
system is explained in terms of functions of organs. The age differences
suggest that children’s theory is built on the application of empirical knowledge.
The results indicated that the acquisition of the concept of digestion leads to a
conceptual revision and enrichment by the age ten.
Similarly if the conceptualisations of students of stage2 (ages 11 and 12) are
considered, their conceptualisation about digestion, role of various organs or
sequence is better than the students of stage1. They could not identify nutrients
in food items which shows their lack of content knowledge about nutrients and
hence balanced diet also. Most students do not identify what nutrients common
food items have and what is missing in a balanced diet .They identify fats and
carbohydrates easily. They know the importance of vitamins, minerals and
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proteins, but cannot identify in food items. They understand the process of
digestion better than younger students, but most still have to conceptualise the
absorption of digested substances from intestines. The physical process of
transformation of food during digestion is understood. Chemical transformation
process takes place with the help of glands is conceptualised by many, but the
absorption and assimilation is not understood by most students.
The students of 13 years have conceptualised most concepts related to food
and nutrition inquired of them. They did not find most concepts difficult except
one concept on the relation between food and growth. Conceptualisation of it
will require understanding of particulate nature of matter and conservation of
matter. However, around 28% of students intuitively understand the relation
between food and growth shows that students at this age are probably
cognitively ready for abstract concepts like particulate nature of matter
.Osborne et al (1992) too have pointed out that an understanding of digestive
process requires a particulate view of matter and this is conceptually difficult for
children. Students may not understand digestion unless they are able to
comprehend that foods are transformed and broken down into blood. The
development of a particulate understanding involves matter such as food being
reducible to microscopic level at which it can be transported around the body.
Although the shape is changed during digestion, the total amount of matter
(food) does not change. The research on children’s understanding of the
particulate nature of matter by Brook et al (1984) showed that almost one fourth
of students aged 15 were incapable of understanding such idea. However, the
study by Skamp (1999) presents evidence that upper primary students can be
taught about the particulate nature of matter in a meaningful way.
According to Coleman G (2005), many nutrition concepts are abstract
concepts. However there are reasons to introduce nutrition concepts in
elementary school rather than wait until children are in the operational stage
where they begin to grasp abstract concepts. Educators might miss many
opportunities to promote understanding of nutrition if they wait until children are
able to comprehend abstract concepts because children are exposed to
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information on food and health messages from many venues including parents,
other people and the media throughout their lives. Providing food and nutrition
information that is concrete and relates to their life experiences can provide a
base for understanding abstract nutrition concepts late in life.
4.6. Conclusion
Due to vastness of the topic food and nutrition, the questionnaires developed to
probe into students understanding of related concepts could focus on limited
but important concepts in each topic. However, analysis of elementary
students’ understanding opened a window into the world of their understanding
of these concepts. Their responses show that though progression of many
important concepts occur across elementary classes, many important concepts
intended at a class are not grasped by them and they have certain alternate
conceptions. Many of the misconceptions are the same as reported in the
literature. The recommendations in terms of improved deliberate pedagogical
interventions to support conceptual understanding of students have been made
by researchers. However, the curriculum developers as well as textbook
authors need to take these into account while organising and sequencing
curriculum across elementary classes
The purpose of this part of the study has been to trace the evolution of
concepts of food and nutrition by elementary students. The analysis of
responses in this part may not provide an exhaustive understanding but
provides a cue for placement of concepts to attain progression.