Transcript File

LIVE, EAT AND BE HEALTHY!
Chapter 6 : The Human Organism and the
Importance of Nutrition
Definitions
Nutrition
The science of food and how the body uses it
in health and disease
Food
Any substance that is ingested and sustains
life.
Nutrient
A substance found in food that is used by the
body to meet important needs
Turn to page 160 in your text book and make
a quick note as to which systems are
involved in the process of nutrition.
6 Main types of nutrients:
•Proteins
•Carbohydrates
•Fats
•Water
•Vitamins
•minerals
Essential
Nutrients
Function
Food
Examples
Location of Broken
breakdown down into
in
digestive
system
Calories
per gram
(cal/g)
Proteins
Construct
and repair
cells
Meat
Beans
Nuts
Stomach
Small
intestine
Amino
acids
4
Fats (lipids) Energy
Butter, oil
Meat
Cheese
Small
intestine
Glycerol
and fatty
acids
9
Carbohydra Energy
tes
Grain
products
Fruits
Veggies
Mouth
Stomach
Small
intestine
Glucose
4
Vitamins
Regulate
metabolis
m
Fruits
Veggies
X
X
0
Minerals
Regulate
metabolis
m
Fruit
Veggies
Meat, milk
X
X
0
Energy Value
Bodies must balance energy they gain from
food and drink with the energy they expend
carrying out our daily activities.
Energy Requirements
 Amount of energy required per individual
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depends on a variety of factors including:
Age
Sex
Weight
Level of physical activity
Overall state of health
Daily Requirements for you
Teenage adolescent Girls:
Between 1800 Cal ( 7200 kJ) and 2400 Cal
(9600kJ)
Teenage adolescent boys:
Between 2200 Cal ( 8800 kJ) and 3200 Cal
(12800kJ)
Measurement
Joule (J): measurement unit for energy adopted
by the International System of Units
Dietary calorie ( Cal): more common term
1Cal= 4000J or 4 kJ
Energy Intake
The following numbers indicate how much
energy is produced per gram metabolized by
the body
 Carbohydrates
=
4 kcal/g
 Protein
=
4 kcal/g
 Fat
=
9 kcal/g
NUTRITION INFO
Nutrient
Kilojoules per
gram (kj/g)
Daily
requirements
in grams (g)
Carbohydrates
Fats
Proteins
17
37
17
500
75
2 g per kg
Canada’s Food Guide
 The rainbow in Canada’s food guide will help
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you choose foods that will supply you with
the right amount of nutrients your body
requires
When looking at Canada’s food guide each
colour represents a different group
Yellow= grains
Green= fruits and vegetables
Blue=milk and alternatives
Red=meat and alternatives
Why?
 Good Nutrition is important for at least 2
reasons:
 1) It provides the energy required to carry out
the many metabolic activities that our bodies
require.
 2) It provides us with the essential raw
materials that we need as building blocks but
that our bodies are unable to manufacture for
themselves.
Grains:
Recommended # of servings/day:
 6 for females
 7 males
Make them count!
 Make at least half of your grain products whole
grain each day.
 Choose grain products that are lower in fat,
sugar, or salt.
Milk and Alternatives:
Recommended # of servings/day:
 3-4 for both males and females
Make them count!
 Drink skim, 1% or 2% milk each day.
 Select lower fat milk alternatives: compare the
nutrition facts on yogurts and cheeses to make
wise choices.
Fruits and Vegetables:
Recommended # of servings/day:
 7 for females
 8 for males
Make them count!
 Eat at least one dark green and one orange
vegetable every day.
 Choose vegetables and fruit prepared with little
or no added fat, sugar or salt.
 Have vegetables and fruit more often than
juice.
Meat and Alternatives
Recommended # of servings/day:
 2 for females
 3 for males
Make them count:
 Have meat alternatives such as beans, lentils,
and tofu often.
 Eat at least 2 food guide servings of fish each
week.
 Select lean meat and alternatives prepared
with little or no added milk or salt.
Examples of a serving:
Grains: 1 slice of bread;1/2 a bagel, pita or tortilla;
30 g of cold cereal or ¼ cup of hot cereal;1/2 cup
of cooked pasta, rice or couscous.
Fruit and Vegetables: ½ a cup of frozen or canned
veggies; ½ a cup of 100% juice; 1 fruit.
Examples of a serving:
Milk and Alternatives: 1 cup of milk;1 cup of
fortified soy beverage; ¾ cup yogurt; 1.5 oz
cheese.
Meat and Alternatives: 2tbsp peanut butter; ¼
cup shelled nuts/seeds ¾ cup cooked
legumes; cooked fish,1/2 cup shellfish,
poultry and lean meat.
Nutrition Facts: Reading a
label
 Example:
 Note serving size
 % daily value is based
on a 2000 calorie
diet
% Daily Value (DV)
 The % DV helps you see if a specific amount
of food has a little or a lot of a nutrient.
 5% DV or less is a little of the nutrient
} This applies to all nutrients
 15% DV or more is a lot of the nutrient
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Note that the Food and Drug Administration (FDA) has not set a Daily Value for trans
fat, and health experts recommend avoiding trans fat to lower your risk of
cardiovascular disease. Similarly, there is no established Daily Value for sugar.
Recommended Macronutrient
Consumption
Protein
10-35%
Fat
20-35%
Carbohydrate
45-65%
Low Fat
 Low fat foods often contain a fair amount of
sugar to maintain flavour
 People don’t necessarily consume less energy
 this determines whether you gain weight
or not
 What can sugar be converted to?
Trans fat
 Similar to saturated fats
 Increase concentration of LDL
 Reduces concentration of HDL
Vegetarian Diet
Vegetarian Diet
 Attempt to avoid meat or fish on moral or
other grounds, although most consume dairy
and eggs.
Vegans
 Vegetarians who in addition to meat and fish
do not consume dairy or eggs.
Issues with Herbivores
Issues
 Restrictive vegetarian diets may limit a persons
protein intake.
 They too have Iron, and B12 deficiencies
Solutions
 To increase protein, eat a diet rich in whole grains,
beans and vegetables .
 To increase iron intake, eat dried beans, brewer’s
yeast , spinach and dried fruits.
 To increase B12, eat fortified cereals, sunflower
margarine and fermented soya products.
Dietary Supplements
 Eating a well balanced diet should provide the
recommended amount of vitamins and nutrients
 Supplements should only be required/used when:
 Ill
 Planning to have children
 Suffering from digestive problems
 Following a special diet
 Recovering from an injury
 Consuming more than the recommended levels
can in fact cause harm
Exercise is important!
Why Exercise?
 Raises your metabolism, burns calories
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 more muscle = more calories burnt at rest
Strengthens your bones (important for
females)
Increases muscular endurance
Helps you avoid injuries
Increases confidence and self-esteem
Improves coordination and balance
Decreases risk of cardiovascular disease
Improves mood
Body Mass Index
 The body mass index (BMI) is a person's weight in
kilograms (kg) divided by their height in meters
(m) squared.
 The National Institute of Health defines normal
weight, overweight, and obesity according to the
BMI rather than the traditional height/weight
charts.
Issues with BMI
 Men and Women are different, so why should
adult men and women have exactly the same
BMI?
 Short adult women have higher BMI than
taller women.
 Race/ethnicity and nationality affect body
composition and BMI.
 Muscular people, athletes and bodybuilders
particularly, have high BMI values, but are not
fat.
Weight Management
 Depends largely on 2 factors:# calories
absorbed through food intake and the
number expended through body metabolism
and physical activity
Maintain a healthy weight by:
 A diet high in nutrients and low in calories
 Reduce caloric intake
 Reduce fat intake
 Increase physical activity
Obesity in Canada
 Increase  More dramatic in children
 Major causes: poor diet and inactivity
 A man’s life expectancy is reduced by 20 yrs if
obese when 20
 for women it’s reduced by 8 yrs
 Food consumption must be adapted to
activity levels, body composition, and
changing hormone levels (generally just with
age)
Underweight
 BMI < 18.5
 1998-1999 – 1 in 10 Canadians
 Women are 3 times more likely
 Women are more likely to try and lose weight
 can start as early as age 9
Underweight
Signs of Disordered Eating:
 Preoccupation with food and weight
 Repeatedly expressed concerns about being fat
 Increasing criticism of one’s body
 Frequently eating alone
 Use of laxatives
 Trips to the bathroom during/following meals
 Continuous drinking of diet soda or water
 Compulsive, excessive exercise
 Complaints of always being cold
Dehydration
 Heat-regulating centre: hypothalamus
1) Reflex dilation of skin:
 Forces blood to flow and transfer heat to skin
2) Sweating Reflex:
 Sends excess fluid to the surface to evaporate
 These cool and dehydrate the body
Other ways to lose water:
 Urine, feces, & breathing
Fluid Replacement
Before Exercise:
 Start well hydrated
 2-3 cups of fluid containing carbohydrates 2-3
hours before
 1 cup 10-20 minutes before
During Exercise:
 If > 50 minutes – a sports beverage with carbs
 Carbohydrate concentration of 6-8%
 6% electrolyte-carbohydrate solution
 Drink at least one ½ cup fluid after each 10 mins
Electrolytes
 Medical/scientific term for salt
 Main salts required by the cells of a body are :
Na+ and Cl Cells need these to maintain voltages across
membranes and carry impulses-nerve muscle
contraction etc.
 Certain concentration needed to prevent
dehydration
 Gatorade, poweraid etc.
Antioxidants