Nutrition & Diets

1. Nutrition & Diets Basic Health Care; HCE100

2. Essential Nutrients • Nutrition (definition) = all body processes related to food • Ingestion • Digestion • Absorption • Circulation • Storage • Metabolism • Elimination • 6 essential nutrient groups • Carbohydrates • Lipids • Proteins • Vitamins • Minerals • Water

3. Carbohydrates • Also called sugars, saccharides • Major source = plants (vegetables, fruit, grains) • Abbreviated “CHO” • Contain only 3 elements • Carbon • Hydrogen • Oxygen • Function • Main fuel that provides energy for all body processes • Simple sugars used • Key is glucose • Main energy for the body = ATP (adenosine tri-phosphate) • Provides fiber for good digestion & elimination • Complex sugars used • Plants: cellulose & starch • Animals : glycogen

4. Lipids (fats) • Building block of all fats = fatty acids • 3 common types of fats in humans • Triglycerides --- commonly called fat • This is way fat is stored & transported in the body • Phospholipids • These are mainstay of cell membranes • Steroids (sterols) • Main one = cholesterol • All other steroids come from cholesterol • Include sex steroids, corticosteroids, vitamin D, bile • Transported by lipoproteins * HDL – high density lipoproteins * LDL – low density lipoproteins • Functions • Good energy source • Insulation • Cushioning

5. Fats are basically hydrocarbons • Animal fats --- saturated ---- all carbons bonds filled • Thick at room temperature • Plant fats --- unsaturated ---- not all carbon bonds filled • Liquid at room temperature

6. Protein • Made up of building blocks called amino acids • Usually large molecules with 3-D shapes • Contain nitrogen besides carbon, hydrogen, & oxygen • functions; • Structural integrity --- collagen, keratin • Functional --- hemoglobin, globulins (antibodies), many hormones • “biological trinity” ----- DNA, RNA, Protein

7. Vitamins • Essential for life, but cannot make most of them; need to ingest them • Can make A, D, & K in body but need precursors • A precursor = ? • D precursor = ? • K precursor = ? • Main function = to serve as coenzymes in metabolic processes • 2 major types • Water soluble ---- B & C [ urine = water soluble] • Fat soluble ------- A, D, E, K • Concept of free radicals • Oxygen very electronegative; thus it steals electrons from other elements • They then become “free radicals” • Need “antioxidants” to neutralize them • Vitamins A,E, & C thought to be good antioxidants

8. Minerals • Inorganic elements essential to life • Key • Sodium • Potassium • Calcium • Phosphorus • Chloride • Iodine • Zinc • Copper • Have many metabolic functions

9. Utilization of Nutrients • Key steps: (1) digestion (2) absorption (3) metabolism • Digestion • Breaks food down to its basic components • Protein into amino acids • Fats into fatty acids; cholesterol as is • Carbs into monosaccharides (glucose) • Complex chemicals into basic elements • Occurs in upper alimentary canal • Mouth, stomach, duodenum

10. Absorption • Nutrients taken up by body via transportation system • All things, except fats, taken into venous blood • Fats into lymph via lacteals • Storage sites in body if not immediately used • Amino acids into cytoplasm of all cells • Glucose into liver as glycogen • Triglycerides into body fat stores • Calcium & phosphorus into bone • Occurs in: • Jejunum • Ileum • Ascending colon

11. Metabolism • Definition = the work of the body • One must build things up (anabolism) • One must break things down (catabolism) • These things are always chemicals • Work needs energy (power to make it happen) • Key body energy = ATP (adenosine triphosphate) • Fuel to generate the energy = glucose • Rate at which body uses energy to maintain itself : • BMR --- basal metabolic rate • Energy measured in calories Metabolic Nutrients → glucose → ATP (energy) → kinetics

12. Calories • Measure of energy produced (really measuring heat) • BMR for adult = 30 cal/ kg (1 kg = 2.2 lb) • Avg adult = 70 kg or 150 pounds • Of the 3 organic basic nutrients: • Protein: generates 4 cal/gm • Sugars: generate 4 cal/gm • Fats: generate 9 cal/gm • The more activity you do the more energy (calories) you need • Key to proper nutrition = COUNT CALORIES !!!

13. Maintenance of Good Nutrition • Food guide pyramid • 5 major food groups major nutrient provided • Carbs: bread, grain sugars • Vegetables vitamins & minerals • Fruits vitamins & minerals • Milk products fats • Meat , fish, eggs protein Note servings/ day - Most 3/ day - Grain 6/ day

14. In 2005 USDA released “new” pyramid • Key difference; it takes activity into consideration • Big negative----- it’s confusing

15. Therapeutic Diets • Regular diet --- based on food guide pyramid • Liquid diet • Clear liquid -- key = water & sugar----- e.g. apple juice, jello • Full liquid --- key = water, sugar, particles ------ e.g. soups • Soft diet • Food with very little chewing required • Bland diet • Consists of easily digested foods • Avoid raw foods, fibered foods, spicy foods, etc • Used for people with G-I diseases • Diabetic diet • CHO intake changed from 40% to 60 % of the diet

16. Calorie- controlled diets • High calorie --- for people with chronic wasting • Low calorie --- for losing weight • Low cholesterol diets • Low sodium diets • Used for people with hypertension