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Unit 9: Nutrition
Nutrition Overview
 Nutrition supports tissue growth, repair,
function
 Digestion: process of breaking down food into
smaller and smaller pieces so we can
eventually absorb the nutrients from it
 Starts in the mouth: enzymes/chewing
 Continues in stomach: hydrochloric acid
 Finishes in small intestine: enzymes
Digestion
Nutrition Overview
• Metabolism: the sum of all the chemical
reactions in your body.
– Building it up (anabolism) and breaking it down
(catabolism)
– Main location = liver
• Nutrition: “the act or process of nourishing or
being nourished”
• Diet: “food and drink regularly provided and
consumed”
Main categories of nutrients
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Fats
Provide energy
Carbohydrates
Proteins
Vitamins
Minerals
The most vital nutrient
Water
Major Categories Nutrients
• Carbohydrates: metabolized to simple sugars
like glucose, a ready source of energy that
circulates the body
– Provide 4 kcal/ g of energy
– Ex. Pastas, breads, fruits and vegetables
Major Categories of Nutrients
• Fats: essential parts of cell membranes and
some hormones. Provide insulation to warm
body.
– Provide 9 kcal/g of energy
– Ex. Canola oil, butter, meat fat
Major Categories of Nutrients
• Vitamins: organic compounds our body needs
to function normally that it must obtain from
the diet because it can’t make them itself
Major Categories of Nutrients
• minerals: a naturally occurring solid
compound found on the periodic table
• They support Biochemical processes
– Both vitamins and minerals provide 0 kcal/g
Water
• Most essential nutrient
• Human body ≈ 60% water by weight
(depending on size)
• Many body processes require it
• Maintains blood pressure
• Readily available from beverages and
fruits/vegetables
Proteins
• Mostly responsible for growth and repair of
tissues.
– Provide 4 kcal/g of energy. However, are only
really used for energy when everything else has
been used up
Protein
• Made from amino acids
• The body can make most amino acids except for a
few (9) which are essential amino acids (EAA).
– We have to get them from our diet!
• Proteins from plant foods are “incomplete”
meaning that they only contain some EAAs but
not all
– But two incomplete proteins together may make a
complete protein = complementing amino acids
Modern North American Diet
• Biggest problem = nutritional excess
– Affluence?
– Convenience foods?
– Perceived shortage of time?
Modern Canadian diet
Modern North American Diet
 Getting too much of everything and in the improper
proportions
 Too much saturated fat
 Half of carbohydrates from baked goods
 65% of B. Columbians not eating recommended
amounts of fruits and vegetables
 77% not eating recommended amounts of calcium.
 However, we are concerned about our fat, starch, fibre
intake and are taking steps to fix it (especially women)
6 Principles of a Healthful Diet
ABCD-MV
• Adequacy- are you getting enough of what you need?
• Balance- getting a good balance of all food groups
• KiloCalorie control- are your energy consumption
patterns matching your expenditure ones
• Nutrient Density- for the amount of kilocalories you are
taking in, are you getting a good amount of nutrients?
• Moderation-not too little or too much of anything
• Variety- a range of food items from each food groups
Nutrient Density
DIETARY GOALS FOR NORTH
AMERICANS
Reduce total caloric intake
• One Calorie (as we know it)= 1,000 calories = 1
kcal
• The key is to eat selectively, portion control
– Buy smaller plates
– Think of restaurant meals as 2 meals
– Consume nutrient dense foods
– Control hunger by consuming filling foods such as
protein/fibre, eating smaller meals throughout day
• We consume, on average, 18% more calories a
day than 30 years ago
Reduce total fat intake
• Fat is associated with higher calorie intake as well
as increased serum cholesterol
• Associated with some forms of cancer: breast,
colon
• Often it’s not the original source of food that is
high in fat, but the manner in which it is prepared
• Cut fat off meat before cooking, choose low fat
cheeses/spreads, dab extra fat off pizza, avoid
friend foods, fill a spray bottle with oil to grease
pans, BBQ, broil, bake
Reduce proportion of saturated fat and
increase the proportion of unsaturated fat
 Saturated fat = solid at room temperature ( ex. Bacon fat).
 Animal fats typically high in saturated fat, while plant fats are
typically low in saturated fat
 However, palm-oil/ coconut oil = high in saturated fat
 Unsaturated fat typically found in plant oils
 Is actually “good fat”
 Fish oil is one of the best kinds because it also has omega-3
fatty acids and reduces the risk of CVD
Choose a diet low in cholesterol
• Found mainly in animal products
• Eggs, liver, kidney, shellfish all high in
cholesterol
• However, dietary cholesterol only raises serum
cholesterol if the person is sensitive to dietary
cholesterol
• Recall: for most individuals to lower serum
cholesterol, they need to consume a diet low
in _______________
Increase Dietary Fibre
 Fibre = is a carbohydrate that we are not able
to break down in our body to use for energy
 It is “filler”, passing through the digestive tract
without being absorbed.
 Add bulk to your diet, thus possibly reducing
appetite
Increase Dietary Fibre
 Soluble fibre:
 Lowers total and LDL cholesterol
 Regulates blood sugar
 Ex. Fruits, legumes and oats (oat bran)
 Insoluble fibre:
 draws water into the stool making it larger and
softer
 Speeds passage of food through the digestive tract
 Ex. Cereals, grains (wheat bran), vegetables
Increase consumption of complex
carbohydrates
• Complex carbs are found in grains, cereal, pasta and potatoes
• Take longer to absorb than simple carbohydrates (ex. Glucose,
fructose)
– Therefore regulate blood glucose levels, which is preventative
against __________________
• Contain more dietary fibre, richer sources of vitamins and minerals
• Look for “100% whole wheat”, “whole grain”, “whole oats”, “whole
rye” on labels. Just because something says “whole wheat” doesn’t
mean it is a complete whole grain. Check you labels!
Use Salt and Sodium in Moderation
• Table salt = sodium chloride
• North Americans typically consume more than 3
times the RNI for sodium!
• Sodium is added to a lot of products upon
processing
• Sodium may increase blood pressure, which can
cause a __________ in an artery leading to
_______________
• Salty foods are a risk factor for some digestive
cancers
– Irritates cells lining the stomach
Ensure adequate iron intake
• Iron deficiency can lead to anaemia, which is a
lowered ability of the blood to transport oxygen
• Leads to decreased energy levels
Ensure adequate iron intake
Two forms of iron:
• Heme iron from animal products. Ex. Beef, liver, heart
– Easier to absorb
• Non-heme iron from plants. Ex. lentils, beans
– Not as easy to absorb into digestive tract
• Absorption of non-heme iron is improved if
eaten together with a heme-iron source
• Overall, Iron absorption improved by vitamin
C, inhibited by coffee/tea
Ensure adequate Calcium intake
 Many vital processes in your body require
calcium
 Also a major component of bones/teeth
 Prevents osteoporosis, which is especially
relevant to post-menopausal women
 Smoking has the opposite effect of calcium!
Increase consumption of foods
containing vitamins A and C
• Vitamins C / A (beta-carotene) are powerful
antioxidants
– An antioxidant prevents the action of oxidizing
agents in the body that damage cells and can lead
to cancer (as well as aging poorly)
• Increase consumption of dark orange and dark
green veggies
• Cabbage family veggies (arugula, bok choy...)
are especially good anti-oxidants
Drink Alcohol in moderation
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Contains 7 kcal/g (more than carbs and proteins!)
One regular beer = 150 kcal
One glass white wine = 100 kcal
One shot of vodka = 60 kcal
“empty calories”
Alcohol should NEVER be consumed during
pregnancy!
Eat a variety of foods
• That way if some foods aren’t providing you
with the nutrients you need, others will
• Eliminates boredom!
Vegetarian Diets
• Do not contain meat
• Types of vegetarians:
– Vegans: eat NO animal products of any kind; this
includes milk.
– Lacto-ovo-vegetarians: don’t eat fish but eat milk
products and eggs
– Lacto-ovo-pesco vegetarians: don’t eat red meats
but eat fish, milk, eggs
• Not really vegetarians!
Health Benefits of a Vegetarian diet
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Prevents/ reverses coronary artery disease
Lowers serum cholesterol and LDL
Lowers incidence of hypertension
Lowers mortality from type 2 diabetes
Lowers incidence of lung/ colorectal cancer
May decrease breast cancer and kidney
damage
Other Benefits of Not Eating Animal
Products
– Animal products tend to be expensive
– Protein rich diets may be high in fat, low in fibre
– Meat/ dairy more likely to contain pathogens
– Animals concentrate heavy metals such as
mercury in large fish
– Better use of land resources
Nutrient Deficiencies associated with
the vegetarian diet
• Typically eat less protein, however, it is often
enough
• Iron is harder to absorb from plant food
• B-12
• Calcium
• Vitamin D
Reading Labels
• As of Dec 2007, all manufacturers had to conform to new and
extremely strict labelling standards in Canada.
• New labels contain:
- The common name of the food
- A net quantity declaration
- The name and address of the dealer
- The durable life date of the product
- A list of ingredients (in decreasing order by weight, volume,
count
- A nutrition facts table (next slide)
• They can also contain:
– Nutrient content claims– ex. ‘low in fat’; ‘reduced sodium’
– Health claims– ex. “a diet low in saturated fat is associated with decrease
incidence of heart disease. Product X is low in saturated fat
Nutrition Facts Table
• All labels in Canada must
contain the following
information
• Nutrients expressed in %Daily
Value for ease
• Check to make sure the serving
size matches how much you
are consuming!
NUTRITIONAL CONCERNS OF THE
DEVELOPING WORLD
Water
• People need approximately1 litre water/
day to survive
• In the third world, 1/3 people have access
to clean drinking water
• Estimated that 17-25 diseases relating to
water could be reduced by 50-100% with
ample clean drinking water
Energy and Protein
• Lack of calories and protein impairs growth
– Small females have more difficulty carrying/having
children
• Lack of calories and protein increases
susceptibility to disease
– Our immune cells need energy/protein to
function!
– Malnutrition often a contributing cause of illness
• Ex. measles
Nutrient Deficiency:
Kwashiorkor
• Another important function of protein is to
maintain water balance
• Lack of protein leads to fluid accumulation in
the abdomen
Obesity in the third world
• As standard of living increases, so do obesity
rates
• Egypt, Mexico have very high rates of
childhood obesity
– Both have a stable and growing economy