“Fad-Diets”Presented October 21, 2004

IVCC Chemistry Club

National Chemistry Week 2004Julie Sherbeyn – Health & Wellness Instructor

Some History…

early mid 1830 1890 1938 1972 1978 1979 1981 1990’s 1990’s 2002

A. Agatston:•South Beach Diet

G. Harrop:•Liquid Diet (skim milk & bananas)

H. Tarnower:•Scarsdale Diet(high protein, low calorie)

J. Mazel:•Beverly Hills Diet (all fruit)

B.Sears:•The Zone Diet (40, 30, 30)

H. Fletcher:•“The Great Masicator•Low meat•High carbs & veggies

R. Atkins:•Atkins Diet (high protein, low carb)

N. Pritikin:•Pritikin Diet (low fat) D. Ornish:

•Vegetarian and extremely low fat

S. Graham:•Vegetarian•No: alcohol, tea, or coffee•Yes: crackers

http://www.channel4.com/science/microsites/B/bodystory/fat_diets.html

2000 Dietary Guidelines Aim for fitness

Aim for a healthy weight. Be physicall active each day.

Build a healthy base Let the Pyramid guide your food choices. Eat a variety of grains daily, especially whole grains. Eat a variety of fruits and vegetables daily. Keep foods safe to eat.

Choose sensibly Choose a diet that is low in saturated fat and cholesterol and

moderate in total fat. Choose beverages and foods to moderate your intake of sugars. Choose and prepare foods with less salt. If you drink alcoholic beverages, do so in moderation.

Fig. 6.2: The food guide pyramid

©2001 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.

The Mediterranean diet

©2001 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.

©2001 Wadsworth, a division of Thomson Learning, Inc. Thomson Learning ™ is a trademark used herein under license.

Biochemistry…

Energy Sources Carbohydrate Fat Protein

Fat metabolism Ketosis

Catabolism Positive and Negative nitrogen balance

Atkins_p.pdf

How much?

Carbohydrate 55-60% Fat 30%

Saturated < 10%

Protein 10-15% Most adults - 0.8g/kg BW Nonvegetarian endurance athletes – 1.2 to 1.4g/kg BW Nonvegetarian strength athletes – 1.6 to 1.7g/kg BW Vegetarian endurance athletes – 1.3 to 1.5g/kg BW Vegetarian strength athletes – 1.7 to 1.8g/kg BW

(Body Weight in pounds / 2.2 = kg BW)

Energy Balance…

Input is energy consumed as calories from food.

Output is energy expended at rest, eating, and in activity.energy in = energy out: weight change

energy in > energy out: weight

energy in < energy out: weight

The answer…

Eat less.Exercise more.

Lose weight.

So UnAmerican!

References:

Johnson, R., Kennedy, E. The 2000 Dietary Guidelines for Americans: What are the changes and why were they made? Annual Editions: Nutrition 04/05, 16th ed. Dubuque, IA: McGraw-Hill/Dushkin, 2004.

Hales, D. An Invitation to Health, 11th ed. Belmont, CA: Wadsworth Thomson Learning, 2003.

Thompson, J. and Manore, M. Nutrition: An Applied Approach, San Francisco, CA: Pearson Education Benjamin Cummings, 2005.

McArdle, W., Katch, F., and Katch, V. Exercise Physiology: Energy, Nutrition, and Human Performance, 3rd ed. Philadelphia, PA: Lea & Febiger, 1991.