food & nutrition section 38-1 yummy! biology 392
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FOOD & NUTRITION
Section 38-1Yummy!
Biology 392
Do you know…?
• How many days can you survive without food?• How many days …….without water?• What important nutrient are vegetarians at
risk of missing in their diet?• Is it OK to exceed the recommended amount
of vitamin supplements?
Why do we need food?
• ENERGY • BUILDING NEW MOLECULES– Proteins– Cell membrane– DNA
Nutrition
Definition The study of food and its effects on the body
Measured in CALORIES amount of heat energy needed to raise the temp. of 1 gm(1mL) of water by 1 degree Celsius
1 Calorie = 1 kilocalorie = 1000 calories
You need about 2200 C (♀) to 2800 C (♂) per day
NUTRIENTS
• Your body can extract energy & nutrients from almost any type of food
6 Major Nutrients include: Water Carbohydrates
Vitamins Proteins Minerals Fats (lipids)
WATER
• The most important nutrient• Every cell in the body needs water to
complete many of the body’s processes and chemical reactions
• Water loss causes problems in all body systems
CARBOHYDRATES*
Major source of Energy2 Forms
SIMPLE• Ex: simple sugars– Fruits, honey, sugar cane
• Mono- & di-saccharides
COMPLEX• Ex: Starches– Grains, potatoes,
vegetables
• Ex: Cellulose/Fiber– Lettuce, bran, whole
grain breads– Cannot be broken down,
but important for moving food efficiently.
FATSFUNCTION: Manufacture cell membranes, produce
certain hormones, store energy
2 FORMS• Saturated contains only single bonds– Ex: butter, lard, other animal fats– Solid at Room Temp
• Unsaturated 1 or more double or triple bonds– Ex: Vegetable oils– Liquid at Room Temp
PROTEINS• FUNCTION: Provides body with material for
growth & repair Make up parts of muscles, skin & organsAre enzymes!
• FORMS: 20 common amino acids– Body can naturally produce only 12– Diet must supply other 8• Called ESSENTIAL amino acids
VITAMINS• DEFINITION Organic molecules that are
needed by the body to help perform important chemical reactions
• FUNCTIONS see pg 974• 14 Essential Vitamins • FORMS 2– Fat- Soluble (A,D,E,K) stored in fatty tissues– Water-Soluble (C,B) cannot be stored
MINERALS• DEFINITION Inorganic nutrients the body
needs, usually in small amounts– Found in periodic table
• FUNCTION see page 975– Examples: Ca (bones); Fe (needed for
hemoglobin); Mg (normal function of nerves and muscles)
• Lost in sweat, urine and other wastes.
Summary Questions1. What are the 6 nutrients needed by the
body?2. What would happen if you did not eat enough
carbs & fats?3. Vegetarians may sometimes take dietary
supplements. What, specifically, might they be missing in their meatless diets?
4. You ate a lot of oranges last week for a nice, healthy dose of vitamin C. Must you eat an orange today? Why?
How do you know what to eat?
• Nutritionists have analyzed how much of each nutrient you need and what foods contain the combinations of each.
• This info is compiled in the “food pyramid”
Old Food Pyramid
New Food Pyramid
General Dietary Recommendations:
· 3 to 5 servings of vegetables · 2 to 4 servings of fruits · 2 to 3 servings of milk, yogurt & cheese · 6 to 11 servings of bread, cereal, rice, & pasta · 2 to 3 servings of meat, poultry, fish, dry
beans, eggs & nuts · Use fats, oils & sweets sparingly
Just what is “One Serving”?
Milk products group: · 1 cup about 8 oz. of milk or yogurt · 2 slices of cheese, 1/8" thick (1½ oz.) · 2 cups of cottage cheese · 1½ cups of ice milk, ice cream or frozen yogurt
Meat group: · 2 oz. to 3 oz. of cooked lean meat, poultry, or
fish · 2 eggs · 7 oz. tofu · 1 cup cooked legumes or dried beans or peas · 4 tablespoons peanut butter · 1/2 cup nuts or seeds
Vegetables: · 1/2 cup cooked vegetables · 1/2 cup raw chopped vegetables · 1 cup raw leafy vegetables · 1/2 to 3/4 cup vegetable juice
Fruits: · 1 whole medium fruit (about 1 cup) · 1/4 cup dried fruit · 1/2 cup canned fruit · 1/2 to 3/4 cup fruit juice
Bread and Cereals: · 1 slice bread · 1 medium muffin · 1/2 hot dog bun or hamburger bun · 1/2 bagel or english muffin · 4 small crackers · 1 tortilla · 1 cup cold cereal · 1/2 cup cooked cereal · 1/2 cup rice · 1/2 cup pasta
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