NUTRITION
Lecture V
Nutrition (nourishment) is the provision,
to cells and organisms, of the materials
necessary (in the form of food) to
support life.
Food Choices
•Personal preference
•Habit
•Ethnic heritage or tradition
•Social Interactions
•Availability, convenience
•Advertising:
•Economy: They are within your means.
•Emotional comfort:
They can make you feel better for a while.
•Body weight and image:
Positive or negative associations:
Positive: They are eaten by people you admire or they
indicate status, or they remind you of fun.
Negative They were forced on you or you became ill
while eating them.
Nutrients in Food
Energy Yielding Nutrients
Non Nutrients in Food
Dietary Reference Intakes (DRI)
A daily nutrient level estimated to meet the
requirements of half the healthy individuals in a
particular life stage and gender group.
•Used to determine nutrient adequacy to reduce risk of
chronic disease or other disorders.
•Used to calculate RDA’s.
DRI’s consist of four values
•Estimated average requirements
•Recommended dietary allowances
•Adequate intakes
•Tolerable upper limits
Recommended Dietary Allowance (RDA)
The average daily dietary intake level that is
sufficient to meet the nutrient requirements of
nearly all (97–98%) healthy individuals in a
particular life stage and gender group.
Adequate Intake (AI)
The average daily nutrient intake level based
on observed or experimentally-determined
approximations or estimates of nutrient intake
by a group (or groups) of apparently healthy
people that are assumed to be adequate.
Tolerable Upper Intake Level (UL)
The highest average daily nutrient intake level
likely to pose no adverse health effects to almost
all individuals in the general population.
As intake increases above the UL, the potential
risk of adverse effects increases.
Energy Recommendations
Nutrient Recommendations
•Estimates of energy and nutrient intakes apply to
healthy people
•Recommendations are NOT minimum requirements
•Recommendations are NOT optimal for all people
•Recommendations should be met by consuming a
varied diet
•Recommendations apply to average daily intakes
•Each DRI category serves a unique purpose
A nutritious diet has FIVE characteristics
Adequacy:
foods provide enough of each nutrient, fibre and energy
Balance:
not choosing one food/nutrient over another
Calorie control:
eating enough to maintain a healthy weight
Moderation: foods high in fat, salt, or sugar can be
eaten as part of a healthy diet if not eaten to excess.
Variety: necessary in order to get all the nutrients one
requires.
How do we determine what we should eat?
•Government agencies provide us with nutrition
recommendations and guideline.
•Recommendations based on scientific research
•These recommendations are translated into food
groups and serving sizes of foods
Other foods
Food Labels
Who Speaks on Nutrition?
Main Sources of nutrition information:
•Product Labels
•Radio/TV
•Friends/relatives/ Colleagues
•Magazines
•Physicians
•Dietitian/Nutritionist
•Internet
Fads, Frauds and Quackery
Food Faddism is defined as the adoption of an unusual
pattern of food behavior, that promotes short-term
weight loss, usually with no concern for long-term
weight maintenance (Fad Diets)
Cabbage soup diet
Grapefruit diet (Hollywood Diet)
Quackery
Is the promotion for profit
of a medical scheme or
remedy that is unproven or
known to be false
Who Falls Victim to Quackery
People who are:
•Unsuspecting, if it appear in the media, its TRUE
•Believe in Magic, i.e., believe there is an easy solution
•Desperate, i.e. those with serious health problems
•Alienated, i.e. have a deep distrust of governments,
medical profession, food companies, etc.