Chapter 7Chapter 7

Nutrition:Nutrition:

Eating For Optimal HealthEating For Optimal Health

Many Dietary Choices • Exotic and foreign foodsExotic and foreign foods• dietary supplementsdietary supplements• artificial sweeteners/flavorsartificial sweeteners/flavors• no-fat, low-fat & artificial no-fat, low-fat & artificial

fatsfats• cholesterol free, high cholesterol free, high

protein, high- protein, high- carbohydrate & low caloriecarbohydrate & low calorie

Healthy EatingHealthy Eating• HungerHunger……..a physiological need to ……..a physiological need to

eateat• Energy requirement in today’s societyEnergy requirement in today’s society• work, school, history, preferencework, school, history, preference• cultural preferences for FOODcultural preferences for FOOD• economic status economic status • food security issuesfood security issues

• AppetiteAppetite…… desire to …… desire to eat…..associated with hunger….more eat…..associated with hunger….more psychological…..psychological…..

NutritionNutrition

Science of foodScience of food• relationship between physiological

function and essential elements in food

NutrientsNutrients• proteins,carbohydrates (CHO),

fats, vitamins, minerals & Water (H2O)

“Diets of Affluence”

• high fat & calorieshigh fat & calories• red meat / potatoes/ rich desertsred meat / potatoes/ rich deserts• recent trends…..more white meats recent trends…..more white meats

and more fruits and vegetablesand more fruits and vegetables

• BUT!!!!! Heart disease, cancer, BUT!!!!! Heart disease, cancer, hypertension, cirrhosis of the hypertension, cirrhosis of the liver, tooth decay and chronic liver, tooth decay and chronic obesity……. obesity…….

…………..still major health risks!..still major health risks!

•A preoccupation A preoccupation of foodof food

•eating too much eating too much of the wrong foodsof the wrong foods

•disordered eatingdisordered eating

Responsible Eating: Responsible Eating: Changing Old HabitsChanging Old Habits

• Consume more calories Consume more calories then we needthen we need

• calorie - a calorie - a measurement of energy measurement of energy potential in foodpotential in food

• CHO:CHO: 4 Kcal/g 4 Kcal/g• FAT:FAT: 9 Kcal/g 9 Kcal/g• PROTEIN: 4 Kcal/gPROTEIN: 4 Kcal/g

Nutrition

PROCESS:

nutrients are absorbed from thenutrients are absorbed from the

small intestine into bloodstreamsmall intestine into bloodstream

for use by cells for use by cells

metabolized into usablemetabolized into usable

compoundscompounds

for building/repair/muscularfor building/repair/muscular

work.work.

NUTRITION IS IMPORTANTFOR…………

• energy production for energy production for muscular work growth muscular work growth and synthesis of body and synthesis of body materialsmaterials

• providing materials for providing materials for tissue maintenance tissue maintenance

• regulation of bodily regulation of bodily processesprocesses

The Digestive Process

• Provides the body with chemicals Provides the body with chemicals for energy and body maintenancefor energy and body maintenance

• essential nutrients delivered via essential nutrients delivered via food intakefood intake

• broken down to be absorbed and broken down to be absorbed and delivered to cells delivered to cells 3,000,000,000,0003,000,000,000,000

The ProcessThe Process…………………….…………………….Start:Start: Mouth - salivary glands (saliva) -

prepares food / moistens / breakdown

Esophagus Tube:Esophagus Tube: 20 to 25cm - connects mouth to stomach

Stomach:Stomach: HCL acid + food + enzymes =

mixture mucus lines stomach for

protection

Small Intestines: Small Intestines: 8 meters long

3 parts - duodenum, jejunum & ileum

secretes digestive enzymes + liver pancreas (Fats, Proteins + CHO)

Nutrients are Absorbed Into Blood

The Liver:The Liver:• determines determines

destination - stored, destination - stored, sent to cells, organs sent to cells, organs or excretedor excreted

The Large Intestine:The Large Intestine:solid wastes (fiber, solid wastes (fiber,

water,salts etc)water,salts etc)

The CalorieThe Calorie

• Calorie:

• a unit for measuring the energy of food - 1 calorie produces enough energy to raise the temperature of 1g of water 1 degree

• caloric measurements are made in thousands of calories therefore the term calories is interchangeable with Kilocalories ( kcal.)

RDA (Recommended Dietary Allowance)

• the levels of nutrient the levels of nutrient intake that is intake that is necessary for the necessary for the maintenance of good maintenance of good nutrition of practically nutrition of practically all healthy persons.all healthy persons.

Factors causing variations in food requirements:

• AgeAge• sexsex• physical sizephysical size• activity levelactivity level• pregnancypregnancy• convalescenceconvalescence

Energy BalanceEnergy Balance

Isocaloric BalanceIsocaloric Balance

Positive BalancePositive Balance

Negative BalanceNegative Balance

CARBOHYDRATES (CHO’s)• compound consisting of compound consisting of

carbon,carbon,

hydrogen and oxygen (Chydrogen and oxygen (C66HH1212OO66))

• most efficient energy source most efficient energy source both immediate and time both immediate and time releasedreleased

• average Canadian diet has 46% average Canadian diet has 46% kcal from CHO;kcal from CHO;

• energy yield = 4 Kcal/g.energy yield = 4 Kcal/g.

Main function….. CHO’sMain function….. CHO’s

• energyenergy

• also rich in vitamins, minerals, also rich in vitamins, minerals, and water.and water.

• when CHO enters the body, it when CHO enters the body, it is converted to glucose, the is converted to glucose, the energy source for cells (very energy source for cells (very important for nervous system important for nervous system and brain).and brain).

Categories of Carbohydrates:

SIMPLE: c-c-c-c-c-c

COMPLEX CHO: c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c-c

Simple SugarsSimple Sugars

• composed of one or composed of one or two simple sugar two simple sugar units (fructose, units (fructose, glucose and glucose and galactose)galactose)

• found mainly in fruitsfound mainly in fruitsprovide immediate provide immediate energyenergy

Two forms of simple sugar:

Monosaccharides:Monosaccharides:• consist of one molecule consist of one molecule

of sugar - the structural of sugar - the structural unit of simple CHO unit of simple CHO (fructose, galactose, and (fructose, galactose, and glucose).glucose).

Disaccharide:

combination of Monosaccharides combination of Monosaccharides includes sucrose, which is table includes sucrose, which is table sugar - combination of 1 fructose sugar - combination of 1 fructose plus 1 glucose moleculeplus 1 glucose moleculeLactose (milk products) = 1 Lactose (milk products) = 1 glucose plus 1 galactose glucose plus 1 galactose moleculemolecule

Maltose = 2 glucose moleculesMaltose = 2 glucose molecules

PROCESSED SUGAR PROCESSED SUGAR CONSUMPTION IN CANADACONSUMPTION IN CANADA:

Mean consumption for each Canadian Mean consumption for each Canadian over 15 years = 150 lbs. of sugar per over 15 years = 150 lbs. of sugar per year - 75% in form of processed foods year - 75% in form of processed foods and beveragesand beverages

• This represents more than 20-25% of This represents more than 20-25% of caloric intakecaloric intake

• 33 teaspoons of sugar per day = 6 33 teaspoons of sugar per day = 6 stalks of sugar canestalks of sugar cane

• tooth decay tooth decay

DISADVANTAGES OF HIGH SUGAR INTAKE

Processed sugars - poor Processed sugars - poor CHO - contain no other CHO - contain no other nutrients i.e. no vitamins nutrients i.e. no vitamins and mineralsand minerals

EMPTY CALORIESEMPTY CALORIES

results in a situation where results in a situation where 100% of nutrients must be 100% of nutrients must be obtained from 75% of obtained from 75% of calories in the diet.calories in the diet.

COMPLEX CHO (polysaccharides)

• composed of three or composed of three or more simple sugars more simple sugars bonded togetherbonded together

• found in grains, fruits, found in grains, fruits, stems, roots, and stems, roots, and leaves of vegetablesleaves of vegetables

• provide longer lasting provide longer lasting energyenergy

Three Types of CHOStarches:

plant source - whole grain foods, rice,plant source - whole grain foods, rice,potatoespotatoes

Fiber (Cellulose):not digested by enzymes in small intestine

insoluble: speeds movement of foodsthrough digestive tract, increases fecal bulkand maintains regularity of bowelmovement

CHO……... Soluble fiber: digested inSoluble fiber: digested inthe large intestine (fruits,the large intestine (fruits,veggies oat bran,driedveggies oat bran,driedbeans)beans)

decreases blood cholesteroldecreases blood cholesteroland cardiovascular diseaseand cardiovascular disease

Controls pacing ofControls pacing ofabsorption of CHO intoabsorption of CHO intobloodstream. bloodstream.

Prevents dramatic swingsPrevents dramatic swingsin blood sugar levelsin blood sugar levels

Canadians Should double their Canadians Should double their intake of fiber, bulk, roughageintake of fiber, bulk, roughage…

20 to 30 grams20 to 30 grams

Protection againstProtection against:

• colon/rectal cancercolon/rectal cancer• breast cancerbreast cancer• constipationconstipation• diverticulosisdiverticulosis• heart diseaseheart disease• diabetesdiabetes• obesityobesity

Eat Less Processed Food to Increase Fiber Intake

CARCINOGENS - ?

• skins of fruits & veggies

• fiber from food ratherthan pills/powder

• spread out fiber intake

• drink plenty of liquids

I’m soooo hungryI could eat a

Vegetable!

EATING TOO MUCH EATING TOO MUCH CHOCHO ! !CAN IT BE TRANSFORMED INTO CAN IT BE TRANSFORMED INTO FATFAT?

GlycogenGlycogen

glucose moleculesglucose moleculesbonded togetherbonded together

stored mainly in liver andstored mainly in liver andmusclemuscle

relatively fast energy forrelatively fast energy formusclesmuscles

• EATING TOO MUCH CHO CAN BE TRANSFORMED INTO FAT

FATS Many negative associations with fatMany negative associations with fat

essential for insulation and maintenanceessential for insulation and maintenanceof body temperatureof body temperature

paddingpadding

healthy skin and hairhealthy skin and hair

proper cell functionproper cell function

carrying of fat-soluble vitamins A, D, E,carrying of fat-soluble vitamins A, D, E,K to cellsK to cells

add flavor and texture to our foodadd flavor and texture to our food

high-energy yield = 9 Kcal/ghigh-energy yield = 9 Kcal/g

Two major types: Triglycerides and Steroids

• 95% of total fat in body95% of total fat in body

• excess Kcal are converted to excess Kcal are converted to Triglycerides and stored in adipose Triglycerides and stored in adipose tissue (fat cells)tissue (fat cells)

• each triglyceride is composed of each triglyceride is composed of three fatty acid molecules attached three fatty acid molecules attached to one glycerol moleculeto one glycerol molecule

• fatty acids consist of a chain of fatty acids consist of a chain of hydrogen (H) and carbon (C) atoms, hydrogen (H) and carbon (C) atoms, with a few oxygenwith a few oxygen (O) atomsatoms

TriglyceridesTriglycerides

some Triglycerides are a majorsome Triglycerides are a majorconcern because of the type ofconcern because of the type offatty acid they contain……...fatty acid they contain……...

fatty acids can be saturated orfatty acids can be saturated orunsaturated (monounsaturatedunsaturated (monounsaturatedor polyunsaturated)or polyunsaturated)

SATURATED FATS:

• chains containing the chains containing the maximum number of H maximum number of H atomsatoms

• solid at room temperature solid at room temperature - butter, lard etc., usually - butter, lard etc., usually animal fatanimal fat

• associated with increased associated with increased cholesterol levels.cholesterol levels.

UNSATURATEDUNSATURATED

chains able to hold more H atomschains able to hold more H atomsplant fats, usually liquid at roomplant fats, usually liquid at roomtemperaturetemperature

if room for only 1 H atom =if room for only 1 H atom =monounsaturatedmonounsaturated

if room for more than 1 H atom =if room for more than 1 H atom =polyunsaturatedpolyunsaturated

both mono- and polyunsaturatedboth mono- and polyunsaturatedappear to lower total blood appear to lower total blood cholesterolcholesterol

Steroids (cholesterol):

essential in formation of:essential in formation of:• Vitamin D Vitamin D

• sex hormones (androgen, sex hormones (androgen, estrogen and progesterone)estrogen and progesterone)

• protects nerve fibersprotects nerve fibers

Lipoproteins

• transport mechanism transport mechanism for cholesterol in bloodfor cholesterol in blood

• three types of three types of lipoproteinslipoproteins

• HDLHDL• LDLLDL• VLDLVLDL

HDL (High Density Lipoproteins)

• transports circulating transports circulating cholesterol from blood to cholesterol from blood to liver for metabolism and liver for metabolism and elimination from bodyelimination from body

• the "good" cholesterolthe "good" cholesterol

• help protect against help protect against coronary artery diseasecoronary artery disease

LDL (Low Density Lipoproteins) and VLDL (Very Low Density Lipoproteins)

• transport cholesterol transport cholesterol from digestive tract to from digestive tract to blood - "bad" blood - "bad" cholesterolcholesterol

• associated with an associated with an increase risk of increase risk of coronary artery diseasecoronary artery disease

Exercise HDL, LDL + VLDL, ratio of LDL/HDL

PROTEINS

• carbon (C), hydrogen (H), carbon (C), hydrogen (H), oxygen (O), and nitrogen (N)oxygen (O), and nitrogen (N)

• essential for growth, essential for growth, maintenance, and regulation of maintenance, and regulation of body tissues and processesbody tissues and processes

• all living organisms contain all living organisms contain proteinprotein

• major component of all cellsmajor component of all cells

• help build muscle, bone, skin, help build muscle, bone, skin, and bloodand blood

Proteins• major constituent of antibodies, major constituent of antibodies,

essential part of immune systemessential part of immune system

• aid in formation of hormones aid in formation of hormones such as insulin and thyroxin, such as insulin and thyroxin, which regulate metabolismwhich regulate metabolism

• essential for enzyme formationessential for enzyme formation

• high energy yield = 4 Kcal/ghigh energy yield = 4 Kcal/g

• when CHO or Fat are insufficient, when CHO or Fat are insufficient, protein can be used as an energy protein can be used as an energy source at expense of tissue growthsource at expense of tissue growth

Proteins• extra protein ingested will be broken extra protein ingested will be broken

down to be used as calories or converted down to be used as calories or converted into body fatinto body fat

• proteins are formed from varying proteins are formed from varying combinations of 20 (21, 22 or 23) amino combinations of 20 (21, 22 or 23) amino acidsacids

• amino acids are linked together in a amino acids are linked together in a string and form proteinsstring and form proteins

• amino acids are linked in various combinations to form various types of proteins

Proteins• body makes all but 8 amino acids body makes all but 8 amino acids

- called essential amino acids - called essential amino acids must come from diet (milk must come from diet (milk products, poultry, fish)products, poultry, fish)

• animal protein contains animal protein contains significant amounts of 8 essential significant amounts of 8 essential amino acids, but also contain amino acids, but also contain saturated fat and cholesterolsaturated fat and cholesterol

• any food containing all 8 any food containing all 8 essential amino acids is knownessential amino acids is known as as complete proteincomplete protein

Proteins• no source of vegetables or no source of vegetables or

cereal protein provides all 8 cereal protein provides all 8 essential amino acidsessential amino acids

• 3 combinations of incomplete 3 combinations of incomplete protein which make complete protein which make complete proteinprotein

1. grains and legumes1. grains and legumes

2. grains and milk products2. grains and milk products

3. seeds and legumes3. seeds and legumes

Protein

Ways to ensure adequate proteinintake………...

eat a varied diet containing all eat a varied diet containing all three nutrients: proteins, three nutrients: proteins, carbohydrates and fat; if carbohydrates and fat; if insufficient kcal from insufficient kcal from carbohydrates and fat = body carbohydrates and fat = body uses proteins….uses proteins….

AND How Much Protein Should IAND How Much Protein Should IEat??????Eat??????

Are YOU Eating Enough protein?YearsYears SexSex proteinprotein

(g/kg body wt)(g/kg body wt)16-1816-18 MM 0.880.88

FF 0.810.81

>19>19 MM 0.820.82FF 0.740.74

Adult male of 70 kg (above 19 years) should eat Adult male of 70 kg (above 19 years) should eat 70 X 0.82 or 57.4 g/day70 X 0.82 or 57.4 g/day

2 glasses of milk2 glasses of milk2 eggs2 eggs4 ounces of meat 4 ounces of meat Canadians eat approximately 90 g/day 2 X RDA Canadians eat approximately 90 g/day 2 X RDA *** excess stored as fat or used as energy*** excess stored as fat or used as energy

Athletes Athletes

1.5 g/kg body wt1.5 g/kg body wt

VITAMINS, MINERALS, WATERVITAMINSVITAMINS• complex organic substances found in complex organic substances found in

food, or chemically made, that are food, or chemically made, that are essential in small amounts for bodily essential in small amounts for bodily processesprocesses

• no difference found in food or no difference found in food or chemically madechemically made

• do not provide energy but play a role do not provide energy but play a role in metabolismin metabolism

• deficiency diseases result when deficiency diseases result when inadequate amounts are consumedinadequate amounts are consumed

Grouped According to Solubility

Water SolubleWater Solublenot stored in the body,not stored in the body,need to be replaced dailyneed to be replaced daily

These are……….These are……….

B-group and Vitamin CB-group and Vitamin C

Fat Soluble Vitamins……….stored in the body andstored in the body andcan reach toxic levels ifcan reach toxic levels ifconsumed in megadosesconsumed in megadoses(many times the RNI)(many times the RNI)

Recommended NutrientRecommended NutrientIntakeIntake

Vitamins A, D, E, KVitamins A, D, E, K

can act as antioxidantscan act as antioxidants– – may slow down themay slow down thedestruction of cells destruction of cells

MINERALS

• inorganic elements essentialinorganic elements essentialfor body function/regulationfor body function/regulationcomponents of hormonescomponents of hormones/enzymes/enzymes

• function with vitaminfunction with vitaminabsorptionabsorption

• their potency can betheir potency can bedestroyed by various meansdestroyed by various means- heat, baking soda, etc.- heat, baking soda, etc.

Two Groups of Minerals

Macro-minerals < 5 grams

required in relatively largerequired in relatively largeamounts - (calcium,amounts - (calcium,magnesium, sodium,magnesium, sodium,potassium, phosphorus,potassium, phosphorus,sulfur,chlorine)sulfur,chlorine)

Trace minerals > 5 gramsrequired in small amountsrequired in small amounts

(iron, zinc, manganese,(iron, zinc, manganese,copper,iodine, colbolt)copper,iodine, colbolt)

WATER• most important nutrient of allmost important nutrient of all

• cannot survive for more than cannot survive for more than a few days without water, but a few days without water, but can without other foodscan without other foods

• dehydration can result within dehydration can result within hours and can be fatalhours and can be fatal

• water carries nutrients to water carries nutrients to cells, removes waste, and cells, removes waste, and regulates body temperatureregulates body temperature

• about two-thirds of body mass about two-thirds of body mass is wateris water

H2O and You

• females have about 50% as water females have about 50% as water and males 60%, due to storage of and males 60%, due to storage of water in active tissuewater in active tissue

• - males have greater muscle mass- males have greater muscle mass

• requirements for water intake requirements for water intake daily vary - 6 to 10 cups - daily vary - 6 to 10 cups - depending on environment and depending on environment and activity levelsactivity levels

HH22OO

• water lost through water lost through urination, urination, perspiration, perspiration, breathingbreathing

• 5% loss could result 5% loss could result in fatigue, loss of in fatigue, loss of concentration concentration physical abilityphysical ability

• 15% loss could result 15% loss could result in deathin death

OPTIMAL NUTRITION THROUGHOPTIMAL NUTRITION THROUGH FOOD CHOICESFOOD CHOICES

proportion of CHO, protein and fatproportion of CHO, protein and fatis essential. Current percentage ofis essential. Current percentage ofcalories from different nutrients is,calories from different nutrients is,for the average Canadian, not infor the average Canadian, not inthe appropriate "balance”the appropriate "balance”

basic dietary guidelines should bebasic dietary guidelines should be

consideredconsidered

fat <30%fat <30%

protein about 12%protein about 12%

CHO about 58%CHO about 58%

A Balanced Diet….. HOW?• one way to achieve balanced one way to achieve balanced

diet is to consider the diet is to consider the number of daily servings of number of daily servings of each of the four basic food each of the four basic food groupsgroups

• lifestyle of the average lifestyle of the average college student today and college student today and the impact of "fast foods".the impact of "fast foods".

• fast foods are excessively fast foods are excessively high in sodium, fat, simple high in sodium, fat, simple CHO and caloriesCHO and calories

Normal Eating vs. A Diet• potential for the potential for the

development of certain development of certain problemsproblems

• too much sodium - too much sodium - relates to water relates to water retention = high blood retention = high blood pressurepressure

• inadequate intake of inadequate intake of vitamins and mineralsvitamins and minerals

• excess caloric intake, excess caloric intake, etc.etc.

NUTRITION AND THE CONSUMER

Be aware of food additivesBe aware of food additives - used to:- used to:

• maintain or enhance maintain or enhance nutritional valuenutritional value

• help in processing or help in processing or preparationpreparation

• maintain freshnessmaintain freshness

• make food more appealingmake food more appealing

Labeling: Usually two kinds of info:

• nutritional info. per nutritional info. per serving i.e. serving serving i.e. serving size, calories per size, calories per serving; protein, fat serving; protein, fat and CHO per and CHO per serving;serving;

• percentage of RDA.percentage of RDA.

VEGETARIANS• obtain majority of nutrients from plant obtain majority of nutrients from plant

sourcessources

• may be vegetarian: vegetables + legumes may be vegetarian: vegetables + legumes onlyonly

• lacto-vegetarian: eat vegetables + lacto-vegetarian: eat vegetables + legumes plus milk productslegumes plus milk products

• lacto-ovo-vegetarian: vegetables + lacto-ovo-vegetarian: vegetables + legumes, milk plus eggslegumes, milk plus eggs

• each of above presents different each of above presents different challenge in terms of receiving all the challenge in terms of receiving all the RDA of nutrients requiredRDA of nutrients required

VEGETARIANS………….

• specifically vitamins D, specifically vitamins D, B12 and riboflavin can B12 and riboflavin can be a problem. Also, zinc, be a problem. Also, zinc, calcium and iron may be calcium and iron may be difficult to includedifficult to include

• lack of calories for lack of calories for children vegetarians can children vegetarians can be a problembe a problem

ATHLETES:• optimal performance optimal performance

sound nutritional statussound nutritional status

• information and information and misinformation relates to misinformation relates to athletic nutritionathletic nutrition

• protein needs - usually too protein needs - usually too much is consumed in the much is consumed in the mistaken belief thatmistaken belief that

• since muscles are made of since muscles are made of protein then high protein protein then high protein diets will help build musclediets will help build muscle

Athletes• CHO - energy for CHO - energy for

performance is essential. performance is essential. Should be primarily Should be primarily coming from complex CHOcoming from complex CHO

• 60-70% CHO, 15% 60-70% CHO, 15% protein, 25-30% fatprotein, 25-30% fat

• important to replenish important to replenish within two hours for within two hours for optimal glycogen synthesisoptimal glycogen synthesis

STRESS• generally agreed that diet is generally agreed that diet is

related to stress. Foods can related to stress. Foods can produce stress response e.g. produce stress response e.g. caffeine = pseudo-stressorscaffeine = pseudo-stressors

• Stress can impact to deplete Stress can impact to deplete certain nutrients, such as certain nutrients, such as Vitamin CVitamin C

• poor nutrition can result in poor nutrition can result in greater susceptibility to the greater susceptibility to the effects of stresseffects of stress

DEVELOPMENTAL ISSUES

• Nutritional needs change Nutritional needs change throughout the life spanthroughout the life span

• importance of adequate diet for importance of adequate diet for pregnant womenpregnant women

• requirements for infants & requirements for infants & childrenchildren

• reduction in caloric need with reduction in caloric need with increasing ageincreasing age