Nutrition

Macronutrients - large amounts
1. WATER
  1. Medium for biochemical reactions, transports, removal of waste and maintenance of body tempreature
2. CARBOHYDRATES
  1. Primary sources of energy, fibre, cell markers, component of DNA
  2. Monsaccharides
    1. Glucose
    2. Frutose
    3. Galactose
  3. Disaccharides
    1. Maltose
      1. glucose + glucose
    2. Sucrose
      1. glucose + factose
    3. Lactose
      1. glucose + galacose
  4. Polysaccharides
    1. Glycogen
      1. Very little exists in food, glucose storage form for animals • Store glycogen in liver and muscles • Serves as an important energy reserve
    2. starch
      1. • Plant cells store glucose as starch • Two forms: amylose and amylopectin • Food sources: rice, oats, beans, lentils, potatoes
    3. Fibers
      1. Structural components of plants • Not available to humans as a source of energy • Either: soluble (viscous) or insoluble
        Fibre helps us stay healthy • Promotes a feeling of fullness (satiety) • Reduces energy consumption • Acts as laxative, to prevent constipation • Reduces the risk of colon cancer • Lowers blood cholesterol - LDL
  5. Digestion • Salivary amylase in mouth • Pancreatic amylase in small intestine • Intestinal enzymes – lactase, maltase, sucrase • Glucose, fructose and galactose are the final products
    1. Absorption • Glucose, fructose and galactose absorbed into blood to be taken to the liver via the portal vein • Viscous fibre is fermented into various acids and gases by bacteria in the large intestine • Non-fermentable fibre escapes digestion and is excreted in faeces
  6. Glycogenesis
    1. Carbohydrate is stored in liver and muscle as glycogen
    2. During excess energy intake, excess carbohydrate is converted to glycogen but when glycogen stores are full, metabolism shifts so that more glucose is used for energy
      1. If that does not restore glucose balance then the liver converts breakdown products of glucose to fat which is transported to adipose tissue
  7. When is glucose required
    1. When a person has not eaten recently - glycogen will be broken down to release glucose
      1. As glucose availability and glycogen stores depleted, body switches to use fat, which can result in a building up of ketones - ketoacidosis • Occurs with prolonged fasting, very low carbohydrate diet , uncontrolled diabetes mellitus
  8. Glycaemic Index (GI)
    1. Glycaemic Index: A value that indicates the potential of foods to raise blood glucose and insulin levels  Glucose 100, Fructose 20, Sucrose 59, Maltose 100
3. LIPIDS/FATS
  1. energy, insulation, absorption of some vitiamins
  2. Facts - insoluble in water, 95% lipids in food are fats and oils, 99% of lipids in body are triglycerides, are composed of carbon, hydrogen and oxygen
  3. Triglycerides: Fats - solid at room temp butter, Oils:liquid at room temp Phospholips: lecithin, cell membrane Sterols: Plant sterols, cholesterol
    1. consist of 3 fatty acids + a 3 carbon glycerols
    2. fatty acids: organic acid with a chain of carbon and hydrogen atoms attached
      1. Methyl end
      2. Acid end - carboxyl group
  4. Saturated fats
    1. No carbon double bond, maximum number of H - coconut oil, butter, palm oil (more saturated a fat is, the more solid it is at room temperature)
  5. Polysturated fats
    1. MOre than one double bond, contains less hydrogens, food sources: cottonseed oils, corn oils, oily fish
  6. Monounsaturated
    1. Only on carbon double bond, two missing hydrogens - olive oil, canola oil and cashew nuts
  7. Lipid digestion
  8. Lipids in the body
    1. Energy storage
      1. Between meals stored as adipose in muscle tissue. At rest.low intensity exercise, 30-79% of fuel is provided by lipid metabolism. during aerobic ecercies, lipids are mobiliised from storage to fuel muscles
    2. Structural functions
      1. Cell membrane
    3. Protection, insulation, transport of fat soluble vitiamins, falvour and texture
  9. Dietary cholesterol and blood cholesterol
    1. Dietary cholesterol 0 source: meat, eggs, fish,dairy products - DOES NOT raise LDL cholesterol as much as saturated or trans fats
    2. Liver manufactures cholesterol from CHO/PRP/Fat ---Accumulating blood cholesterol in the artery walls  the formation of plaque  atherosclerosis  heart attacks and stroke
    3. Plant sterols: Strucutres are similar to cholesterol - margarine, functional food
  10. Essential fatty
    1. Essential Fatty Acids (EFAs) o Linolenic acid (omega-3): • 18 carbons and 2 double bonds • 1 st double bond is located on the 3 Carbon from methyl end • Two metabolic derivatives of omega-3: eicosapentaenoic acid (EPA) and decosahexaenoic acid (DHA) rd • Best source – oily fish (mackerel, salmon and sardines) • Other sources - Vegetable oils, walnuts, flaxseeds o Linoleic acid (omega-6): • 18 carbons and 3 double bonds • 1 st double bond is located on the 6 carbon from the methyl end • Sunflower, corn, soy, peanut oils, vegetables Why are they essential? th Must be consumed in the diet, since the body cannot manufacture them
4. PROTEINS
  1. structures of the body, enzymes and energy
    1. made of carbon, hydrogen, oxygen and nitrogen
      1. 8 proteins are provided in food
  2. Proteins help: Growth and maintance, enzymes and hormonzes. immune system
  3. Insufficant proteins in teh blood streem - excessive amount of fluid -oedema
  4. Recommended protein intake
    1. 10-35% total energy intake
    2. Increase in pregnancy, lactation, active people/vegetarians
    3. High protein diets
      1. Increase callicum loss, weakend bones
      2. Huigh protein foods may be high in fats and cvholesterol
      3. Extra strain on liver and kidneys - dehydration.
5. ENERGY DENSE: Carbohydrates: 4 kcal/16.8kj/ Proteins: 4 kcal/16.8 kj/g Lipids: 9 kcal/ 37.8 kj/g Alcohol: 7 kcal/29.4 kj/g
MicroNutrients - smal amounts
1. Vitamins - ORGANIC
  1. regulation of metabolism, co-catalysts for enzymes
  2. Fat-soluble
    1. A (Retional/Beta-Carotene)
      1. Found in red/orange fruit. dark green veg, dairy prodcuts
        Needed for eyes, bone development, immune function
        Deficiency - Nightblindness
    2. D (calciferol)
      1. Dairy products, liver and fish, sunlight
        Increased calcium absorbtion, bones
        Deficiency: Rickets, Osteoporosis
    3. E (tocopherol)
      1. Meat, veggie (avocardo)
        Fights free radicals (antioxidant)
        Deficiency: Haemolysis, Anaemia
    4. K (Menadione)
      1. leafy veg, gult flora
        Blood clotting factors
        Deficiency: Bleeding
    5. Potentially harmful in excess, "low fat" diet inadequate intake. do not readily cross the placenta
  3. Water-soluble
    1. B
      1. B3 - Niacin, Nicotinamid
        Energy metabolism - forms coenzymes
        Meat, liver, poultry, fish,
      2. B6 - Pyridoxine
        AA metabolism - promotes PRo
        Meat, liver, poultry, fish
      3. Folate, folacin, Folic acid
        Co enzyme for DNA and RNA
        Meat. nuts, fruit, potatoes
      4. B2 - Riboflavin
        Energy metabolism - forms coenzyme with FAD, skin
        Dairy, meat, liver, eggs
      5. B1 – Thiamine
        Energy metabolismpromotes CHO metabolism – Promotes central nervous system function‘Beri Beri’ –
        Whole-grain cereals, fortified bread, pulses, potatoes, legumes, nuts, pork, ham, live
      6. B12 - Cobalamin
        Co enzyme for Dna to RNA
        Meat, Fish, shellfish, eggs
    2. C - ascorbi acid
      1. citrus fruits, leafty greens,
        Collagen, Iron
        Scurvy
    3. Not stored in the body, excess is excreated in urine, more easily lost during cooking, act as a coenzyemes (would stay in tact during reactions to be used again)
2. Minerals - INorganic
  1. structural for bones and teeth, electrolyres for muscles contraction and never impuluses, water balance
  2. Macrominerals >100mg
    1. Electrolytes -ect
      1. NA+
      2. K+
    2. Structural
      1. CA2+
      2. Phosphate
  3. Microminerals -<100mg
    1. Trace elemants
      1. Fe, I, F, ZN
    2. Unknown function
      1. Boron, bromide
    3. Toxic in small amounts
      1. Lead, mercury, cadmium
Non Nutrient molecules
1. Dietary fibre
2. Antioxiddants
3. Omega 3 fatty acids
4. Phytochemicals e.g. betacarotene
Functional foods - processed foods with added ingredients
1. Omega 3 enhanced eggs, cereal fortified with vitamins and minerals (milo)
Nutriceuticals: dietary supplements that provides health benifits
1. Medical form rather than food
NZ reccomendations
1. AMDR (Acceptable macronutrient distribution range): an estimate of the range of intake for each macronutrient for individuals (expressed as per cent contribution to energy), which would allow for an adequate intake of all the other nutrients while maximising general health outcome. 
2. SDT (suggested dietary target) A daily average intake from food and beverages for certain nutrients that may help in prevention of chronic disease.

Next up

Nutrition

Description

Resource summary

Media attachments

Similar

	Created by Clarissa Mackay over 9 years ago