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: • 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