©2005 Thomson-Wadsworth

NUTRITION:Staying Healthy

Walter Willet, MD, Chair, Dept. of Nutrition

Harvard School of Public Health:

"With the right food choices, physical activity, and not smoking, we could prevent

-about 80% of heart disease-about 90% of diabetes-about 70% of strokes" Sept. 2011 interview

Nutrition Concept # 1

Food- basic need of humans Food security- access at all times to sufficient

supply of safe, nutritious foods Food insecurity- limited/ uncertain

availability of safe, nutritious foods

Nutrition Concept # 2

Foods provide: Energy (calories) Nutrients Other biologically active

substances

Calories

Not a nutrient

A measure of energy

Macronutrients

Carbohydrates – simple and complex

Proteins - amino acids

Fats- fatty acids . Water

All have 4 calories per gram

Also 4 calories per gram

9 calories per gram

Micronutrients

Phytochemicals (from plants)

#3: Nutrient Needs

All humans need the same nutrients, but not in the same amounts.

The amounts needed vary among people based on such factors as:

Age Pregnancy Body size Breastfeeding Gender Illnesses Genetic traits Environment Growth Status

Recommended Dietary Allowances (RDAs)

Updated every five yearsStandard desired levels of essential nutrient

intake in healthy peoplePrevent deficiencies, promote health and

help prevent chronic disease Different RDAs

Based on age and gender for women, different if pregnant or breastfeeding

4. Malnutrition

• From poor diets: either inadequate or excessive calories and nutrients in the body

• From diseases or genetic factors that interfere with the body’s ability to use the nutrients consumed

• Or from a combination of these factors

Health Problems

Today’s chronic health problems are from diets and lifestyles greatly different from our early ancestors

Bodies Haven’t Changed

Biological processes in the body were developed more than 40,000 years ago

These evolution-driven processes are firmly linked to the genetic makeup of humans

Maximized survival of the species Genes change very little over great spans

of time

Our Natural Diet

Fruits, roots, vegetables, insects, grubs, fish, and wild game

To sustain a physical lifestyle Current foods have little resemblance to foods of

our early ancestors Sugar, salt, alcohol, and fats such as oils,

margarine, and butter, weren’t in ancestor’s diets Current lifestyles are inactive

What’s Wrong with our Diets?

Human body functions best on low saturated fat, sugar, and sodium, lean sources of protein, high in fiber, complex carbohydrates, and vegetables and fruits

Modern diet:• High in processed foods

• loaded with fat and sugars • high in sodium

• Low in vegetables and fruits • Low-calcium and/or vitamin D diets

Typical modern diet and lifestyle cause

Overweight and obesity Cardiovascular disease

mainly heart attacks and strokes Cancer, especially breast and colon cancer Diabetes “Malaise”

Nutrient Density

Fig. 1-11, p. 18

Why is U.S. diet hazardous to health?

Trends Toward Trends Toward Colossal CuisineColossal Cuisine

1977 20001977 2000

1977 2000

Healthy Eating Pyramid

Additional calcium for young

women

Can Americans Change? Yes, we can!

What diet changes should you make

to stay healthy? Reduce portions of meats and cheese Eat more fish and plant-based proteins Avoid processed sugars and potatoes Eat more complex carbohydrates, especially

high fiber foods, vegetables, fruits Replace animal fats with vegetable oils Avoid processed foods high in sodium Eat more natural (less processed) foods high in

potassium and magnesium Get adequate Vitamin D

When you want a burger, think small!

How Should You Get Protein?

More Beans & Nuts: Pintos, limas, black

beans, etc Nuts, peanuts,

peanut butter, soy foods (tofu)

Hummous

How Should You Get Protein?

Chicken & Turkey Fish & Shellfish Low Fat Dairy &

Eggs Beef/pork: ~4 oz.

Twice a week

Make meat part of a meal, not the heart of a meal!

Eat big servings of fresh vegetables--any vegetables you can eat raw--

you never need to measure them, just enjoy!

Don't Drink Sugar!

20 oz Soda = 4 servings!

60 grams carbohydrate

Avoid processed sugars and potatoes

Eat more complex carbohydrates-look for 100% whole wheat

-choose beans, brown rice, and whole grains more often

Have at least 3 servings of fruit every day!

The perfect snack— Fresh fruit is best Either frozen or

canned is good Fruit is better than juice

High Potassium Foods Reduce Blood Pressure

Fruits: apricots, banana, cantalope, honeydew melon, mango, nectarine,

oranges and orange juice Vegetables: Dried beans, tomatoes,

spinach, sweet potato, potato, peppers, avocado, and most cruciferous vegetables

(broccoli, cauliflower, cabbage, kale, collard greens)

Eat more foods high in magnesium-look for minimally processed

foods!

Leafy green vegetables

Nuts Beans and peas Whole, unrefined

grains

Avoid processed foods high in sodium

Replace animal fats with vegetable oils

Which is the better meal?

A meal is always better with salad!

Add some fruit whenever you can!

Is this too small?

Boiled potatoes,

about 12 grams

A sandwich is much more satisfying with a side salad—and even better

with a fruit!

Still only 4 carbs

Get Adequate Vitamin D

The Sunshine Vitamin 10-30 minutes a

day in the summer Fortified low fat

milk and soy milk Fortified foods

(few) Vitamin pills:

RDA 600 mg a day

Nutritious foods don’t have to cost more than junk food!

Do-It-Yourself

Hearty Soups are low cost and easy to make!

Easy Step to Better Nutrition

Healthy Exercise Pyramid

TheEnd