Transcript Nutrition & Diets

Nutrition & Diets
Basic Health Care; HCE100
Essential Nutrients
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Nutrition (definition) = all body processes
related to food
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Ingestion
Digestion
Absorption
Circulation
Storage
Metabolism
Elimination
6 essential nutrient groups
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Carbohydrates
Lipids
Proteins
Vitamins
Minerals
Water
Carbohydrates
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Also called sugars, saccharides
Major source = plants (vegetables, fruit, grains)
Abbreviated “CHO”
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Contain only 3 elements
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Carbon
Hydrogen
Oxygen
Function
1. Main fuel that provides energy for all body processes
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Simple sugars used
Key is glucose
Main energy for the body = ATP (adenosine tri-phosphate)
2. Provides fiber for good digestion & elimination
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Complex sugars used
Plants: cellulose & starch
Animals : glycogen
Lipids (fats)
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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
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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
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Good energy source
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Insulation
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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
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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
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Essential for life, but cannot make most of them; need to ingest them
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Can make A, D, & K in body but need precursors
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A precursor = ?
D precursor = ?
K precursor = ?
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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
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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
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Inorganic elements essential to life
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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
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glucose
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ATP (energy)
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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
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Food guide pyramid
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5 major food groups
1. Carbs: bread, grain
2. Vegetables
3. Fruits
4. Milk products
5. Meat , fish, eggs
Note servings/ day
- Most 3/ day
- Grain 6/ day
major nutrient provided
sugars
vitamins & minerals
vitamins & minerals
fats
protein
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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