3.1 Nutrition

• Macronutrients: 

  • Carbohydrates
  • Proteins
  • Fat 
  • Water
• Micronutrients: 

  • Minerals 
  • vitamins
• Functions of carbohydrates:

  • Fuel
  • energy storage
  • cell membrane
  • DNA
  • RNA
• functions of vitamins:

  • enable energy release from macrinutrients
  • promote bone health
  • promote eyesight
  • strengthen immune function
• function of minerals:

  • mineralisation of bones and teeth
  • blood oxygen transport
  • defence against free radicals
  • co-factors for energy metabolism
  • maintenance of acid base balance and cellular fluid balance
• Chemical component of a glucose molecule: CH2O
• This diagram represents the basic structure of a glucose molecule

  
• Monosacchirides are made from one glucose molecule and are easily absorbed by the body.

  Examples of monosaccharides:

  • glucose
  • fructose
  • galactose
• Two monosaccharides combine in a condensation reaction and form a disacchiride with the loss of one molecule of water.

  Example of disaccharide:

  • sucrose
• Polysaccharides are made out of more than 2 monosaccharides combines and are chains longer than 10 molecules

  Examples of polysaccharides:

  • Starch
  • glycogen
• A molecule of triglycerol is composed out of 1 unit of glycerol and 3 fatty acids
• Saturated Fatty acids have single nonds between the individual carbon atoms of the fatty acid chain.

  E.g:

  • meat
  • full fat dairy
  • butter
  • coconut oil
• Unsaturated fatty acids contain one or more double bonds between the carbon atoms of the fattu acid chain.

  E.g:

  • olive oil
  • avocado oil
  • nuts
  • seeds
  • vegetable oil
  • omega 3 fish oil
• Chemical components of a protein molecule:

  • carbon
  • hygrogen
  • oxygen
  • nitrogen

  (CHON)
• Essential Amino Acids cannot be synthasised by the body and must this be obtained by the diet. There are 9 essential amino acids
• Non essential amino acids can be synthasised by the body. There are 11 non essential amino acids
• Current recommendations for a healthy balanced diet:

  • 45-55% Carbohydrates
  • 15-35% protein
  • 20-35% fat
  • 30% from unsaturated fats
  • <5% from saturated fats
  • 3-5% fibre
  • <6 grams of salt
  • 3 litres of water
• approximate energy content per 100 grams of:

  • Carbohydrates: 1760 kJ
  • fats: 4000 kJ
  • Proteins: 1720 kJ
• how the recommended energy distribution of the dietary macronutrients differs between endurance athletes and non athletes:

  Athletes:

  • need as much as 2 times the amount of energy
  • more Carbohydrates as during prolongued aerobic exercise energy is provided by the muscle glycogen stores which directly depend on the amount of carbohydrates consumed
  • carbohydrates prevent the onset of early muscle fatigue and hypoglycaemia
• athltes need:

  • Higher protein intake for recovery after exercise 

   

  • Higher water intake as athletes need to thermoregulate more

   

  Greater vitamin and mineral intake for bone strength and blood cell production and growth