1. NUTRITION
FUNCTION OF NUTRIENTS

2. WATER Essential nutrient 55 – 65% of body weight
Water loss through evaporation, excretion, and respiration

3. CARBOHYDRATES Main source of energy Excess carbs converted to fat
Calorie
Unit measuring amount of energy contained within the chemical bonds of different foods
Empty calories – foods like candy with no nutritional value
Roughage – indigestible part of carbs (cellulose)

4. LIPIDS (FATS)
Source of energy – twice as many calories as same amount of carb or protein
Body fat cushions internal organs, insulates against cold
Fats carry fat-soluble vitamins
Cholesterol
Animal fat found in meat, cheese, eggs
Excess can build up in artery walls causing atherosclerosis
Recommended blood level under 200 mg/dl
HDL – High density lipoprotein – “good”, removes excess cholesterol from cells to carry back to liver to be broken down and eliminated
LDL – Low density lipoprotein – carry fat to cells

5. PROTEINS Many functions: Amino acids are building blocks of proteins
Enzymes
Source of energy
Muscles, hormones, clotting, antibodies all depend on proteins
Amino acids are building blocks of proteins
Complete proteins contain all amino acids – milk, eggs, cheese
Incomplete proteins – do not contain ALL amino acids – vegetables, beans, wheat
Body can’t store amino acids
Adults in US eat too many proteins, putting extra burden on kidneys and liver to excrete

6. MINERALS Inorganic compound needed for human growth and maintenance
Most important:
Sodium
Potassium
Calcium
Iron
Trace elements – present in small amounts, toxic levels close to healthy levels
Most minerals present in average adult diet
Fluorine – in drinking water, for bones and teeth
Iodine – in fish, shellfish, iodized salt, needed to make thyroid hormones
Iron – liver, lean meats, needed to make hemoglobin

7. VITAMINS Biologically active organic compound
Function as coenzyme for normal health and growth, some behave like hormones
A, D, E and K – fat soluble, can be stored in the body
B vitamins and Vitamin C are water soluble, can’t be stored, excess excreted through urine

8. FIBER
Found in plant foods like whole grain breads, cereals, beans, peas, other vegetables and fruit
Important for proper bowel functioning, may lower risk of heart disease and some cancers