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Nutrition & DietsNutrition & Diets
Basic Health Care; HCE100
Essential Nutrients
• Nutrition (definition) = all body processes related to food
• Ingestion• Digestion• Absorption• Circulation • Storage • Metabolism• Elimination
• 6 essential nutrient groups1. Carbohydrates2. Lipids3. Proteins4. Vitamins5. Minerals6. Water
Carbohydrates
• Also called sugars, saccharides
• Major source = plants (vegetables, fruit, grains)
• Abbreviated “CHO”
• Contain only 3 elements» Carbon» Hydrogen» Oxygen
• Function 1. Main fuel that provides energy for all body processes
– Simple sugars used
– Key is glucose – Main energy for the body = ATP (adenosine tri-phosphate)
2. Provides fiber for good digestion & elimination– Complex sugars used
– Plants: cellulose & starch
– Animals : glycogen
Lipids (fats)
• Building block of all fats = fatty acids
• 3 common types of fats in humans
1. Triglycerides --- commonly called fat
• This is way fat is stored & transported in the body
2. Phospholipids • These are mainstay of cell membranes
3. 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
• 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
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
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
1. Water soluble ---- B & C [ urine = water soluble]
2. 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
Minerals
• Inorganic elements essential to life
• Key • Sodium• Potassium• Calcium• Phosphorus• Chloride• Iodine• Zinc• Copper
• Have many metabolic functions
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
• 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
• 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
• 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 !!!
Maintenance of Good Nutrition
• Food guide pyramid– 5 major food groups major nutrient provided
1. Carbs: bread, grain sugars
2. Vegetables vitamins & minerals
3. Fruits vitamins & minerals
4. Milk products fats
5. Meat , fish, eggs protein
Note servings/ day
- Most 3/ day
- Grain 6/ day
• In 2005 USDA released “new” pyramid• Key difference; it takes activity into consideration• Big negative----- it’s confusing
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
• 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