Introduction to Human Nutrition

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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
6
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
7
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
8
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
9
Improving Health
 Risk





factors in your control:
Smoking
Alcohol intake
Over-consumption of calories
Physical inactivity
Poor quality diet
10
Improving Health
 Risk




factors you cannot control:
Age
Gender
Genetics (family history)
Ethnicity
11
Nutrition in the US
 Obesity,

adults, 1988–94 to 2009–10
Decrease desired
12
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.
14
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
15
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
16
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
17
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
18
Classifying Nutrients
There are 6 Classes of Nutrients
1.
2.
3.
4.
5.
6.
Carbohydrates
Lipids (fats)
Proteins
Vitamins
Minerals
Water
19
Body Composition
20
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
21
Classifying Nutrients
nutrients – body can make
from other nutrients ingested
 Nonessential
 Examples:
• Cholesterol
• Some amino acids
22
Classifying Nutrients by
Composition
 Organic
nutrients - contain carbon
• Carbohydrates
• Lipids
• Proteins
• Vitamins
 Inorganic
nutrients - do not contain
carbon
• Minerals
• Water
23
Quantity Needed
 Macronutrients:
need in relatively large
amounts

Carbohydrates, lipids, proteins
 Micronutrients:
need in relatively small
amounts

All other nutrients
24
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
26
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.
27
Energy-Yielding Nutrients
28
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
29
Classes of Carbohydrates
 Simple

sugars
Monosaccharides and disaccharides
 Complex


carbohydrates
Starch
Fibers
 Carbohydrate
rich foods……..
30
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
31
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?
32
Proteins
 Proteins:




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?
33
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
34
Evaluating a Food Label
 _____
grams carbohydrate
 _____
grams fat
 _____
grams protein
 TOTAL
KCAL:
____________
35
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:
37
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
38
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.
42
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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