Why do we need Food?
 Nutrients;
 Provide energy
 Provide building blocks
 Maintain body cells
 essential vs. non-essential

 deficiency causes health problem normal function regained if added back
 biologic function identified

Too much Food
 Too many calories + inactivity = obesity epidemic
 Obesity = health problems

Obesity Trends* Among U.S. Adults
BRFSS, 1991, 1996, 2004
(*BMI  30, or about 30 lbs overweight for 5’4” person)
1991 1996
2004
No Data <10% 10%–14% 15%–19% 20%–24% ≥25%

8 Leading Causes of Death (US)
1. Heart Disease (29%)*
2. Cancer (22%)*
3. Stroke (7%)*
4. Lung diseases (5%)
5. Accidental death (4%)
6. Diabetes (3%)*
7. Flu and pneumonia (3%)
8. Alzheimers (2%)

History of Nutrition
 17001800’s knew certain foods would treat or prevent certain conditions
 Nutritional deficiencies and diseases
 (early 1900-1945) Identification of vitamins and 45 essential nutrients

The Six Classes of Nutrients
 Carbohydrates
 Fats
 Proteins
 Also called macronutrients
 Vitamins
 Minerals
 micronutrients
 Water

 Composed of C, H, O
 Provide a major source of fuel for the body
 Basic unit is glucose
 Simple and Complex CHO
 Energy yielding (4 kcal /gm)

.

 Composed of C, H and few O
 Triglyceride is the major form of lipid
 Fats and oils
 3 classes based on fatty acid chain

Monounsaturated Fatty Acids
 Polyunsaturated Fatty Acids (essential)
 Saturated Fatty Acids
 Energy yielding (9 kcal /gm)

 Composed of C, O, H, N
 Make up bones, muscles, other tissues
 Basic unit is amino acid
 (9) Essential amino acids
 (11) Nonessential amino acids
 Energy yielding (4 kcal /gm)

1.1b

 Composed of various elements
 Vital to life, participate in metabolic pathways
 Needed in tiny amounts
 2 categories:
 Fat soluble
 Water soluble
 Yields no energy

 Inorganic substances
 Needed in tiny amounts
 Some contribute to body structure (calcium)
 2 categories:
 Trace minerals (need less than 100 mg)
 Major minerals (need more than 100 mg)
 Yields no energy

 Composed of H, O
 Vital to life
 Is a solvent, lubricant, medium for transport, chemical processes, and temperature regulator
 Makes up majority of our body (60%)
 Yields no energy

.

Carbohydrates .
Proteins
Vitamins
Minerals
Fat
Body Composition of Healthy-Weight Men and Women
Carbohydrates
Proteins
Vitamins
Minerals
Fat
Water Water

Transformation of Energy
(Calories)
 For muscular movements
 To build new compounds
 For nerve transmissions
 For ion balance

 A measurement of energy (in heat form)

“the amount of heat it takes to raise the temperature of 1 gram of water by 1 degree Celsius”

.

Sample Calculation of a
Nutrition Label
 Per serving
 CHO: 15g x 4 kcal/g = 60 kcal
 PRO: 3g x 4 kcal/g = 12 kcal


FAT: 1g x 9 kcal/g = 9 kcal
TOTAL: 81 kcal, rounded down to 80

Calculation of Contribution to
Total kcals

Assume one day’s intake is 1980 kcal
 290 gm of CHO (x 4 kcal/gm)
 60 gm of fat (x 9 kcal/gm)
 70 gm of protein (x 4 kcal/gm)
 % of kcal as CHO= (290 x 4)/1980 = 0.59 or 59%
 % of kcal as Fat= (60 x 9)/1980 = 0.27 or
27%
 % of kcal as PRO= (70 x 4)/1980 = 0.14 or
14%

The Typical North American Diet
 16% of kcals as proteins
 ~66% from animal sources
 50% of kcals as CHO
 ~50% from simple sugars
 33% of kcals as fat
 ~60 % from animal fats

Data Collection
 Surveys
 Continuing Survey or Food Intake by
Individuals (CSFII)
 National Health and Nutrition Examination
Survey (NHANES)

The Government and Nutrition
 DHHS: Department of Health and Human
Services
 USDA: pyramid and dietary guidelines
 FDA: health claims
 FTC: labeling and false advertising

Food and Nutrition Board: RDA’s

Influences of Food Choices



Not everything on the Internet is true!!

Determination of the reliability of a website
Not everything on the news or in the newspaper is accurately reported!!
Copyright 2005 Wadsworth Group, a division of Thomson Learning

.
.

Gaining Scientific Knowledge

1.
2.
3.
4.
5.
6.
Scientific method
Observation
Hypothesis
Experiments
Theory
Peer Review
Follow-up studies

Generating a Hypothesis through
Observation
1. Epidemiology: The study of diseases in populations
diet-disease pattern
-then forms basis for lab studies
Types of epidemiologic studies
-cross sectional
-case control
-cohort
2. Clinical observations

Copyright 2005 Wadsworth Group, a division of Thomson Learning

Experiments
 Animal Studies
 need animal model: the disease in the animal must closely mimic the disease in humans
 Lab studies (test tubes)
 Human studies (clinical trials)
 Double Blind Study



Typically consists of; experimental group and control group subjects randomly assigned neither researchers or subjects know which group they’re in
 reduces chances of placebo effect

Copyright 2005 Wadsworth Group, a division of Thomson Learning

Copyright 2005 Wadsworth Group, a division of Thomson Learning

Fig. 1.6

Copyright 2005 Wadsworth Group, a division of Thomson Learning

Copyright 2005 Wadsworth Group, a division of Thomson Learning

The Dietary Supplement Health and Education Act (DSHEA) ‘94
 Classifies vitamins, minerals, amino acids, herbal remedies as “foods”


Prevents the FDA from regulating them as heavily as additives or drugs
FDA must prove this “food” is unsafe before it can be pulled from the shelf
 Dietary supplements can be sold without FDA approval

Disclaimer on Claims

“This statement has not been evaluated by the Food and Drug Administration.
This product is not intended to diagnose, treat, cure, or prevent any disease”
 Many people still buy the products

Where to Get Reliable Nutrition
Information
 Accredited University
 Hospital dietetics department
 Well known health entities (e.g.,
American Heart Association,
American Dietetic Association, etc.)
 Registered Dietitian (RD)

Genetics and Nutrition: Is There
A Relationship?
 Genes contain information
 Genes direct growth, development, maintenance of cell
 Genes control expression of individual traits (hair color etc…)
 Genes control susceptibility to diseases

Nutrition, Genetics and Chronic
Diseases
 Heart disease
 Hypertension
 Obesity
 Diabetes
 Cancer
 Osteoporosis

Assess Your Disease Potential
 Family medical history
 Your risk increases if you have more relatives with diseases
 Your risk increases if relationship to relative(s) is closer

Solutions(?)
 Gene therapy
 Nutrition therapy
 Genetic testing

pg.30

Fig. 1.7