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