NUTRITION

CHAPTER 7 SECTION 1

PAGES 176-187

NUTRIENTS• NUTRIENTS: substances in foods that provide energy & materials

for – Cell development– Growth– Repair

• Energy amount needed depends on body mass, age, activity level• CALORIE: the amount of heat necessary to raise the temperature

of 1 kg of water 1 ° C. measures the amount of energy available in food carrots = 30 cal, cheese pizza = 170 cal

• 6 kinds of nutrients available in food

CLASSES OF NUTRIENTS

1. PROTEINS2. CARBOHYDRATES3. FATS4. VITAMINS5. MINERALS6. WATER

ORGANIC VS. INORGANIC NUTRIENTS

ORGANIC• Proteins, carbs, vitamins, &

fats• Contain carbon• Foods with these must be

digested

INORGANIC• Water & minerals• Contain no carbon• Are not digested—absorbed

directly into bloodstream

PROTEINS

• PROTEINS: large molecules that contain carbon, hydrogen, oxygen, nitrogen, & sometimes sulfur

• Used for replacement/repair of body cells & for growth

• Made of amino acids (20 amino acids can combine to make 1000s of proteins)

• Essential amino acids cannot be made in body’s cells—must get them from food

CARBOHYDRATES (carbs)

• Made of carbon, hydrogen, & oxygen atoms held together by energy

• When they are broken down, they release energy

• 3types:1. Sugars—simple carbs2. Starch—complex carbs3. Fiber—complex carbs

SUGARS

• Simple carbs• Examples:– Table sugar– Fruits– Honey– milk

STARCHES

• Complex carbs• Made of chains of simple sugars• Sources:– Potatoes– Foods made from grains (like pasta, bread)

FIBER

• Found in cell walls of plant cells• Cannot be digested, but need to keep digestive

system working properly• Sources:– Cereals– Beans– Peas– Fruits– Vegetables

FATS

• AKA lipids• Provide energy & help body absorb vitamins• 1 gram of fat can release 2X energy as 1 gram

of carbs• Extra energy is converted to fat & stored for

later• 2 kinds: saturated /unsaturated

SATURATED VS. UNSATURATED FATS

SATURATED FATS• Usually solid at room

temperature• Associated w/high levels of

cholesterol• Leads to heart disease or

stroke• Sources:

– Meats– Animal products– Some plants

UNSATURATED FATS• Usually liquid at room

temperature• Sources:

– Vegetable oil– Fats found in seeds

VITAMINS

• Organic nutrients needed in small amounts for growth, regulating body functions, & preventing some diseases

• 2 types: water-soluble (must be taken daily) & fat-soluble (stored by your body)

• Examples:– D: Used by bones; made by skin in sunlight– K: helps blood clot; made by bacteria in large

intestine

MINERALS

• Inorganic nutrients• Jobs:– Take part in chemical reactions– Send nerve impulses throughout body– Carry oxygen to body cells

• Body uses 14 minerals• Calcium & phosphorous are used the most.

WATER

• Body is 60% water by weight• 2/3 is in cells• Rest is around cells & in body fluids• Lose water through perspiration (sweat)• Need to drink 2 liters of liquids a day

HOMEOSTASIS

• The regulation of the body’s internal environment

• Example: body uses thirst to tell you when you need more water

FOOD GROUP

• Foods that contain the same nutrient• 5 groups (My Plate or Food Plate):

1. Bread/cereal: 6– servings daily2. Vegetables: 3-5 servings daily3. Fruit: 2-3 servings daily4. Milk: 2-3 servings daily5. Meat: 2-3 servings daily