Copyright © 2009 Pearson Education, Inc.,publishing as Pearson Benjamin Cummings.
PowerPointPowerPoint®® Lecture Slides prepared by Lecture Slides prepared byJames Bailey, University of TennesseeJames Bailey, University of Tennessee
1C H A P T E R
The Role of Nutrition The Role of Nutrition in Our Healthin Our Health
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
What Is Nutrition?
Nutrition: the study of food, including How food nourishes our bodies How food influences our health
Nutrition is a relatively new discipline of science.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why Is Nutrition Important?
Nutrition contributes to wellness.
Wellness: the absence of disease Physical, emotional, and spiritual health
Critical components of wellness Nutrition Physical activity
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why Is Nutrition Important?
Nutrition encompasses the following aspects of food Consumption Digestion Absorption Metabolism Storage Excretion
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why Is Nutrition Important?
Nutrition also studies these aspects of food Psychological Food safety Global food supply Cultural
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why Is Nutrition Important?
Figure 1.1
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why Is Nutrition Important?
Nutrition can prevent disease. Nutrient deficiency diseases:
scurvy, goiter, rickets Diseases influenced by nutrition:
chronic diseases such as heart disease Diseases in which nutrition plays a role:
osteoarthritis, osteoporosis
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin CummingsFigure 1.2
Why Is Nutrition Important?
Obesity is a growing
problem.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Why is Nutrition Important?
Nutrition is so important that it has become a national goal.
Goals of Healthy People 20101. Increase quality and years of healthy life
2. Eliminate health disparities
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
What Are Nutrients?
Nutrients: the chemicals in foods that are critical to human growth and function.
carbohydrates vitamins
fats and oils minerals
proteins water
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
What Are Nutrients?
Macronutrients: nutrients required in relatively large amounts (g or Kg).
Provide energy Carbohydrates, fats and oils, proteins
Micronutrients: nutrients required in smaller amounts (g or mg).
Vitamins and minerals
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Energy from Nutrients
We measure energy in kilocalories (kcal).
Kilocalorie: amount of energy required to raise the temperature of 1g of water by 1°C.
On food labels, “calorie” actually refers to kilocalories.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Carbohydrates
Primary source of fuel for the body, especially for the brain
Provide 4 kcal per gram Carbohydrates are found in grains (wheat, rice),
vegetables, fruits, and legumes
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Fats and Oils
Are composed of lipids, molecules that are insoluble in water
Provide 9 kcal per gram Are an important energy source during rest or low
intensity exercise Are found in butter, margarine, vegetable oils Are source of fat-soluble vitamins and essential
fatty acids
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Proteins
Are chains of amino acids Can supply 4 kcal of energy per gram, but are not a
primary energy source Are an important source of nitrogen
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Proteins
Proteins are important for Building cells and tissues Maintaining bones Repairing damage Regulating metabolism Fluid balance
Protein sources include meats, dairy products, seeds, nuts, and legumes.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Vitamins
Vitamins: organic molecules that assist in regulating body processes.
Vitamins are micronutrients that do not supply energy to our bodies.
1.Fat-soluble vitamins
2.Water-soluble vitamins
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Vitamins
Fat-soluble vitamins Vitamins A, D, E, and K Dissolve easily in fats and oils
Fat-soluble vitamins can be stored in the body.
Toxicity can occur.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Vitamins
Water-soluble vitamins Vitamin C and the B vitamins Remain dissolved in water
Excess water-soluble vitamins are eliminated by the kidneys and cannot be stored in our bodies.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Minerals
Minerals: inorganic substances required for body processes.
Minerals include sodium, calcium, iron, potassium, and magnesium.
Minerals have many different functions such as fluid regulation, bone structure, muscle movement, and nerve functioning.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Minerals
Our bodies require at least 100 mg/day of the major minerals such as calcium, phosphorus, magnesium, sodium, potassium, and chloride.
We require less than 100 mg/day of the trace minerals such as iron, zinc, copper, iodine, and fluoride.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Water
Water is a critical nutrient for health and survival.
Water is involved in many body processes.
fluid balance nutrient transport
nerve impulses removal of wastes
muscle contractions chemical reactions
many, many more…
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Dietary Reference Intakes (DRIs): updated nutritional standards.
Expand on the traditional RDA values Set standards for nutrients that do not have RDA
values
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
DRIs identify the Amount of a nutrient needed to prevent deficiency
disease in healthy people Amount of a nutrient which may reduce the risk of
chronic disease Upper level of safety for nutrients
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Figure 1.8
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
DRIs consist of four values1. Estimated Average Requirement (EAR)
2. Recommended Dietary Allowances (RDA)
3. Adequate Intake (AI)
4. Tolerable Upper-Intake Level (UL)
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Estimated Average Requirement (EAR) The average daily intake level of a nutrient that will
meet the needs of half of the people in a particular category
Are used to determine the Recommended Dietary Allowance (RDA) of a nutrient
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs: EAR
Figure 1.9
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Recommended Dietary Allowances (RDA) The average daily intake level required to meet the
needs of 97 to 98% of people in a given life stage and gender
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs: RDA
Figure 1.10
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Adequate Intake (AI) Recommended average daily intake level for a
nutrient Based on observations and estimates from
experiments Used when the RDA is not yet established:
calcium, vitamin D, vitamin K, fluoride
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Tolerable Upper Intake Level (UL) Highest average daily intake level that is not likely
to have adverse effects on the health of most people Consumption of a nutrient at levels above the UL is
not considered safe
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Estimated Energy Requirement (EER) Average dietary energy intake (kcal) to maintain
energy balance Based on age, gender, weight, height, and level of
physical activity
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs
Acceptable Macronutrient Distribution Ranges (AMDR)
The portion of the energy intake that should come from each macronutrient
The range of energy intake from carbohydrate, fat, and protein associated with reduced risk of chronic disease
The range of macronutrient intake that provides adequate levels of essential nutrients
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Determining Nutrient Needs: AMDR
Table 1.4
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Nutrition Research
The scientific method Observation: describe the phenomenon Create a hypothesis Design, collect, and analyze the data Interpret the data Generalize the findings, develop a theory
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Research Models
Epidemiological studies Human experiments
Case control studies Clinical studies
Animal studies
Note: Each type of study has advantages and disadvantages.
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Research Study Factors
Controls Does not receive treatment
Sample size Appropriate to measure a difference between
treatment groups
Placebo Similar appearance and taste
Double-blind Neither subjects nor researchers know who is in the
placebo or treatment groups
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Evaluating Media Reports
Ask these questions to determine the scientific validity Who is reporting the information? Who conducted the research and who paid for it? Is the report based on reputable research studies?
Was there a control and an experimental group? Was the sample size large enough to rule out
chance variation? Was a placebo effectively administered? Was the experiment double blind?
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Evaluating Media Reports
Is the report based on testimonials? Are the claims too good to be true? Prior to publication in reputable scientific journals
articles undergo peer review Experiments must be repeated to confirm or
disprove the findings
Copyright © 2009 Pearson Education, Inc., publishing as Pearson Benjamin Cummings
Reliable Sources of Information
Trustworthy experts Registered dietitian (RD) Licensed dietitian Professionals with advanced degree(s) in nutrition Medical doctor