Nutrition

• Nutrition – 2 categories –

– Pure science – looks at how the body uses nutrients

– Social Science – relationship between food and human behavior and the environment.

Why do you eat?

There are 3 main reasons, why we eat.

☻Physical Health☻Environment☻Emotions

Physical Health• Food along with air and water is one of life’s

basic needs.• Eating the right kinds of food

– (fruits, veggies, carb’s, protein, calcium, water)• Help you:

– To stay alive– To stay fit– To be active

• Many of the leading causes of death (cancer, stroke, diabetes, heart attack, etc.) are linked to food in some way.

Environment– Culture- picnics, baseball games, holidays,

birthday parties- Food choices reflect the culture you live in, ethnic background, religious beliefs, teen culture

– Family & social relationships- children pattern their food habits after their role models, what, when, like, dislike,

• As you get older friends may influence your food choices – new foods at their homes,

• Food is usually present at social gatherings, can be given as gifts etc.

Environment

– Media messages- ads are everywhere. TV, magazines, billboards

• Which foods have you bought as a result of an ad? Ads may try to persuade you. Which foods do you see being advertised? Fruits, veggies, fatty foods etc..

– Life-style- Cost, convenience, taste, nutrition, food safety influence food shopping. Time & Money.

Emotions• Think about your eating habits. Are you

eating because you are hungry? Because you are bored, lonely, angry, excited, nervous? Or don’t you eat when you are experiencing the above emotions?

Nutrition Throughout Your Life

At every stage in life, good nutrition is essential for health.

Before you were born

- Proper nutrition is essential for a healthy

baby to be born- 10 months- fast growth

Infant

- Proper Nutrition is essential for proper

growth- 0-2yrs. - Fast growth

Adolescence

- Fastest and most growth you will experience.

- Many teens skip meals or substitute high-fat or sugary foods for more nutritious choices.

Why??

- Nutrients- substances in food that the body needs to function properly. - i.e. growing, repairing itself, supply of energy

Recommended Dietary Allowances (RDAs)

Recommended intakes of nutrients that meet the needs of almost all healthy

people of similar age and gender. These are established by the Food and Nutrition

Board of the National Academy of Sciences.

These nutrients can be grouped into six main categories

1. Carbohydrates2. Fats3. Proteins4. Vitamins5. Minerals6. Water

Note: Each has a unique function in the normal growth and functioning of the body. No one food

provides all the nutrients your body needs.

Carbohydrates

• Carbohydrates- Provide energy- found mainly in plant sources of food

• RDA for 2000 calorie diet• ~55-65% of calories come from carbohydrates mainly

complex carbohydrates• ~130 grams• ~Fruit- 2 cups, vegetables 2 ½ cups, grains 6 oz. (6

servings)• Fiber RDA- 21-38 grams• Eating enough carbohydrates allow protein to be used

for building and repairing the body. When protein is used for energy, it cannot be used for other purposes.

• Sugar RDA- no more than 10% of total calories, or for 2000 calorie diet 200 calories, or 50 grams

There are Two Forms of Carbohydrates

• Simple carbohydrates.

• Complex carbohydrates

Simple carbohydrates• a. Fruits, some vegetables and milk –

natural sugar• b. Table sugar, syrups and molasses

(processed sugars) added to many foods including sweet desserts, candies and soft drinks

Complex carbohydrates

• a. Starches- i.e.• b. Fiber – i.e.

helps move waste through your digestive system and helps prevent constipation, appendicitis and other intestinal problems.

Fats- (Lipids)- fatty substances that do not dissolve in water

RDA based on 2000 calorie diet• ~No more than 30% of calories from fat• ~25-30 grams• ~Servings- use sparingly or no more than

290 calories per day

Role of fat– carry fat-soluble vitamins A,D,E, and K into your blood

without fats our bodies could not use these nutrients.– provides essential fatty acids i.e. linoleic acid

essential for growth and healthy skin.– Add flavor.– Satisfy hunger because they take longer to digest.– Stored energy – it accumulates when people.

consume excess calories from any source.– Cushions your vital organs, protecting them from

injury.– Insulates your body from heat and cold.

Saturated Fats• animal fats (beef, pork, egg yolks, dairy

foods) (chicken and fish are lower) and some vegetable oils (palm, coconut), butter, chocolate, cream soups, croissants, doughnuts

• Usually solid or semisolid at room temperature

Unsaturated Fats

• - vegetable fats (soybean, corn, cottonseed, olive oils)

• Usually liquids or oils at room temperature

Trans fat• Specific type of fat formed when liquid oils

are made into solid fats like shortening and hard margarine. They raise cholesterol which increases your risk of heart disease. Found in crackers, candies, cookies, snack food, fried food and baked goods.

Cholesterol• fatlike substance. Our liver can make the cholesterol it

needs therefore it is not considered a nutrient. Cholesterol is essential to each cell membrane in the human body. The body uses cholesterol to produce vitamin D, certain hormones and the protective sheath around nerve fibers. It also aids in digestion. However in excess it can accumulate on the inner walls of the arteries, causing health problems like heart attack and stroke.

• 2 Types- no more than 300 mg is recommended• Dietary cholesterol- • Serum cholesterol-

Proteins- vital part of every body cell

• i.e. muscle, bone, connective tissue, teeth,

skin, blood & vital organs- all contain protein

Proteins-• RDA based on 2000 calorie diet• 10-35% of total calories• 51 grams for women, 64 grams for males• Servings 5 ½ ozs. of meat and beans and

3 cups of milk (dairy products)

• Athlete recommendation• 125 lb. athlete 63-94 grams• 150 lb. athlete 75-113 grams• 200 lb. athlete 100-150 grams

amino acids

• There are 20 different amino acids-our body can make all but 9 – we need to get those from food

• If you take in too many proteins the excess will be stored as fat

Functions

• Proteins build all body tissues during periods of growth for instance, infancy, childhood, adolescence and pregnancy.

• Proteins maintain all body tissues during periods of growth

• Proteins repair or replace damaged or worn out cells during the rest of our lives

• If you don’t get enough carbohydrates and fats, protein can be used for energy, but then it isn’t building and repairing body tissues

Sources of Protein

• Animal sources ~fish, meat, poultry, eggs, milk, cheese, yogurt

• Plant sources ~Legumes (beans), seeds, nuts, lentils, tofu, many green vegetables

Vitamins• Micronutrients because they are needed in

small amounts• Functions:• Help regulate many vital body

processes• Do not supply calories

2 Types

Water soluble- dissolve in water- Any excess is excreted in urine - Pass easily into blood in the process of digestion- Since no reserves your body needs foods with these vitamins everyday- (Vitamin C, Vitamin B1, B2, B6, B12)

Fat soluble- absorbed and transported by fat- Any excess is stored in the body- Too many can be toxic.

- (Vitamin A,Vitamin E, Vitamin K)

Minerals• Micronutrients the body can’t manufacture • Help regulate many body functions• Examples:

Calcium – building materials of bone and teeth, heart muscle contraction (dairy, leafy veggies)Iron – cell metabolism, rigidity to bones and teeth (peas, beans, milk, liver, meat, cottage cheese, broccoli)Potassium – controls acid-base and liquid balances (bananas, oranges, prunes, meats)Sodium – fluid balance (table salt, milk, meat, fish, poultry)

Recommended intake of sodium: 1500-2400 mg

Minerals

• Females need more iron (menstruation) and calcium (osteoporosis) than men

6. Water- most essential nutrient. - Only oxygen is more important- Our body’s are 2/3 water (60%)

Functions of water:• Water carries nutrients to and transports wastes

from your cells• Lubricates your joints and mucous membranes • Enables you to swallow and digest food• Absorbs nutrients• Eliminates wastes• Perspiration – helps cool body down

Recommended fluid intake: Water, milk, juice.

– Requirements are different for everyone- varies with climate, exercise, individual differences in perspiration

– Thirst is best indicator however a rule of thumb might be– 1 oz / 3 lbs. of body weight– You can also get water from foods you eat i.e. celery 95%,

watermelon 92%, broccoli 91%, potato 71%, cheddar cheese 37%, mixed nuts 2%

• Water contains essential minerals– Taste varies because of where it is coming from. Different rocks

and soil that it passes through. Consumer report – NYC municipal water tastier than most bottled waters.