Transcript Introduction to Human Nutrition

Introduction to Human
Nutrition
Course Web Page
Chapter Outline
 Nutrition
defined (1.1)
 Nutrition and health (1.1, 1.6)

Healthy People 2020 goals (1.5)
 Classifying
the nutrients (1.2)
 Nutritional research
 Hunger and appetite (1.7)

Factors impacting food choices, small group
exercise
2
Nutrition Defined
– the science of foods and
their relationship to health and
disease
 Nutrition
 Study


the:
Nutrients in the foods
action of foods and the nutrients in the body
3
Nutrition Defined
 Actions






in the body include:
Ingestion
Digestion
Absorption
Transport
Metabolism
Excretion
4
Nutritional Goals
 Quality
intake that allows you to
function at your best and promotes
health.

Intake that provides adequate levels of each
nutrient
 Quantity
of intake that promotes a healthy
body weight.
5
Diet and Health
 Diet
- the foods one consumes
•The quality of your daily diet
affects the risk of chronic
diseases

Meaning…..The food choices you
make daily have a cumulative
impact on your health
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Nutrition and Health
 Chronic
health issues associated with diet
include:

Cardiovascular disease
• Heart disease and stroke





Hypertension
Obesity
Type II Diabetes
Osteoporosis
See pages 5/6
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Leading Causes Death - US
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
Heart disease: 597,689
Cancer: 574,743
Chronic lower respiratory diseases: 138,080
Stroke (cerebrovascular diseases): 129,476
Accidents (unintentional injuries): 120,859
Alzheimer's disease: 83,494
Diabetes: 69,071
Kidney diseases: 50,476
Influenza and Pneumonia: 50,097
Intentional self-harm (suicide): 38,364
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CDC, 2010 data
Improving your Health
 Goal
is to reduce the number of risk
factors that are in your control

Risk factor = something that statistically
increases the incidence of a disease
• Risk factors may not be the cause of the disease
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Improving Health
 Risk





factors in your control:
Smoking
Alcohol intake
Over-consumption of calories
Physical inactivity
Poor quality diet
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Improving Health
 Risk




factors you cannot control:
Age
Gender
Genetics (family history)
Ethnicity
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Nutrition in the US
 Obesity,

adults, 1988–94 to 2009–10
Decrease desired
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Sodium Consumption
 Target:
2,300 milligrams
13
Healthy People 2020
 Americans


with a healthful diet:
Consume a variety of nutrient-dense foods
within and across the food groups, especially:
• whole grains, fruits, vegetables, low-fat or
fat-free milk or milk products, and lean
meats and other protein sources.
Limit the intake of saturated and trans fats,
cholesterol, added sugars, sodium (salt), and
alcohol.
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Healthy People 2020
 Limit

caloric intake to meet caloric needs.
All Americans should avoid unhealthy weight
gain, and those whose weight is too high may
also need to lose weight
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What’s Considered Food?
 Foods
are a source of energy
(calories) contain nutrients and are
derived from plant or animal sources
 Nutrients
are substances in foods
that support health


used by the body for energy, and to
support growth, maintenance and repair
of body tissues
~ 40 nutrients identified at this time
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Classifying Nutrients
nutrients – nutrients the body
either cannot make or cannot make
enough of to meet its needs.
 Essential


These nutrients must be obtained from foods
(ingested in some manner)
Examples:
• Vitamins
• Calcium, iron, and other minerals
• Some of the amino acids
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Essential Nutrients
 To



be classified as an essential nutrient:
The biological function of nutrient is known
Omission from the diet leads to a decline in a
biological function
Return of the nutrient restores the biological
function
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Classifying Nutrients
There are 6 Classes of Nutrients
1.
2.
3.
4.
5.
6.
Carbohydrates
Lipids (fats)
Proteins
Vitamins
Minerals
Water
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Body Composition
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Describing the Nutrients
 There
are several ways to classify the
classes of nutrients.




Essential or nonessential
Organic or inorganic
Macronutrient or micronutrient
Energy yielding or not
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Classifying Nutrients
nutrients – body can make
from other nutrients ingested
 Nonessential
 Examples:
• Cholesterol
• Some amino acids
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Classifying Nutrients by
Composition
 Organic
nutrients - contain carbon
• Carbohydrates
• Lipids
• Proteins
• Vitamins
 Inorganic
nutrients - do not contain
carbon
• Minerals
• Water
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Quantity Needed
 Macronutrients:
need in relatively large
amounts

Carbohydrates, lipids, proteins
 Micronutrients:
need in relatively small
amounts

All other nutrients
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Classifying Nutrients
 Energy-yielding
nutrients (3):
Carbohydrates
 Fats (lipids)
 Proteins
 Where does the energy come from?

25
A little more on energy
 Measure


energy in kilocalories in U.S.
What most think of as a “calorie” is really a
kilocalorie
Kcal = amount of energy needed to raise the
temperature of 1 kg of water by 10C
 Measure
energy in kilojoules (kJ) in most
other countries
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Energy in the Body
 The
body uses the energy yielding
nutrients to fuel all activities

All energy yielding nutrients are “caloric”.
 If
more energy is ingested than is needed
to fuel body activities the extra energy is
stored as _________ and ________
occurs.
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Energy-Yielding Nutrients
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Energy-Yielding Nutrients
 Carbohydrates:


C, H, O
4 kcal/gram
Body’s primary source of energy
• Use as glucose
• Glucose is the brain’s only source of energy


Carbohydrate stores are limited ~12-24 hours
(in liver and muscle)
Open to pages 8/9
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Classes of Carbohydrates
 Simple

sugars
Monosaccharides and disaccharides
 Complex


carbohydrates
Starch
Fibers
 Carbohydrate
rich foods……..
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Lipids
 Lipids


– fats and oils: C, H, O
9 kcal/gram
Body’s alternate source of energy
• Use fat along with glucose as an energy source
most of the time

Stores are unlimited
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Types of Lipids
– solids
 Oils – liquids
 Saturated (solids/fats)
 Fats

No carbon to carbon double bonds
 Unsaturated

(liquids/oils)
Carbon to carbon double bond(s) present
 Lipid
rich foods?
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Proteins
 Proteins:

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
C, H, O, N, S
4 kcal/gram (same as _______)
Body’s least desirable source of energy
• WHY? …….
Protein is used for energy only when
carbohydrate is NOT available as an energy
source.
Protein rich foods?
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Energy-Yielding Non-nutrient
 Alcohol
– 7 kcal/gram
 Non-nutrient
because it has no required
function and it


interferes with growth, maintenance and
repair of the body
Alcohol’s metabolites are harmful
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Evaluating a Food Label
 _____
grams carbohydrate
 _____
grams fat
 _____
grams protein
 TOTAL
KCAL:
____________
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6 Classes of Nutrients



•
•
•
Carbohydrates
Lipids (fats and oils)
Proteins
Vitamins
Minerals
Water
Pages 8/9
36
Vitamins
 Essential
 Organic,

micronutrient
may contain C, H, O, N, P, S….
 Not
energy-yielding
 Help reactions occur in the body/cells
 Can be water-soluble or fat-soluble
Examples:
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Minerals
 Essential,
not energy-yielding
 Inorganic, micronutrient


Major minerals: Ca, P, Na
Trace minerals: Fe, Zn (<100 mg/day)
 Some
form compounds -> structural
• Ca and P in bones and teeth
 Some

are ions in fluids ->electrolytes
Na, K….nerve and muscle function
 Indestructible
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Water
 Water
(H2O)

Essential
Organic or inorganic?
Noncaloric

We are ~60% water


39
Not everyone has access to clean water
40
Other important substances in foods
 Phytochemicals

Substances in plant foods that are associated
with health
• Area of MUCH research and false claims!

See page 12
41
Food Choices
 Small



group exercise
What influences your food choices each day?
Why do you eat what you eat?
Get into groups of ~4 and make a list of what
impacts your food choices most days.
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Food Choices
1.
2.
3.
4.
5.
6.
7.
Personal
preferences
Habit
Ethnic heritage
Tradition
Social interactions or
pressure
Availability
Convenience
Economy $
9. Positive or negative
associations
10. Emotional Comfort
11. Values -Religious,
8.
political, environmental
Health concerns
13. Nutritional value
12.
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HAITI
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CHINATOWN - PHILADELPHIA
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Zambia
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LOUISIANA
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