Health

• Six categories of nutrients needed for optimal health and wellbeing

  • Carbohydrates (including fibre)
  • Proteins
  • Fats
  • Vitamins
  • Minerals
  • Water
• Macronutrients


  • Carbohydrates
  • Protein
  • Fats
• Macronutrients


  Needed in large amounts
• Micronutrients

  • Vitamins
  • Minerals
• Micronutrients


  Needed in very small quantities
• Carbohydrates


  • Provide fuel for the body
  • Glucose is the preferred fuel for young people who are growing and require a lot of energy for metabolism and growth
• Carbohydrates should provide the majority of a young person's energy needs
• Carbohydrate breakdown


  1. Carbohydrates are broken down

  2. Glucose molecules are absorbed into the bloodstream

  3. Glucose molecules are stored for later use
• Energy from carbohydrates


  1g of carbohydrates provide 16 kJ of energy
• Major food sources of carbohydrates

  • Vegetables
  • Fruits
  • Grains
  • Breads
  • Pastas
  • Cereals
• Fibre


  A type of carbohydrate found in all foods of plant origin
• Benefits of fibre in the diet

  • Provides a feeling of fullness
  • Slows the absorption of glucose into the blood
  • Reduces the amount of surplus energy consumed from discretionary foods
  • Reduces cholesterol levels and risk of cardiovascular disease
  • Absorbs water and adds bulk to faeces (bowels) to help remove waste
  • Prevents constipation and assists in weight maintenance
• Good sources of fibre


  • Bran
  • Wholemeal breads
  • Grains and seeds
  • Fruit
  • Vegetables (raw where possible)
  • Legumes
• Protein


  • Main function is to build, maintain and repair body cells
  • Can be used as a secondary source of energy
• 1g of protein provides 17kJ of energy
• Protein eaten in excess


  May be stored as adipose tissue (obesity)
• Amino acids


  • Protein is made up of amino acids
  • There are 20 types of amino acids that humans need to function
  • Essential amino acids cannot be synthesised in the body and must be consumed
  • Non-essential amino acids can be synthesised in the body
• Complete protein


  Contains all essential amino acids
• Incomplete protein


  Does not contain all essential amino acids
• Food sources of protein


  • Eggs
  • Milk, cheese and other dairy products
  • Beef
  • Soy products (tofu, soy milk)
  • Legumes
  • Nuts
  • Chicken and other poultry
  • Fish and seafood
  • Wholegrain cereals
• Fats/Lipids


  • Act as a fuel for energy
  • 1g of fat provides 37kJ of energy
  • Foods packed with fats are "energy dense foods"
  • The amount of fat in the diet should be determined by the amount of energy required by the individual
  • Most of the diet should come from carbohydrates
  • Fats are required for the development and maintenance of cell membranes
• Cell membrane


  Responsible for maintaining the structure of cells & allowing the transport of nutrients, gases, waste in/out of cells
• Types of fats


  • Monounsaturated
  • Polyunsaturated
  • Omega 3
  • Omega 6
  • Saturated
  • Trans
• Total fat intake should account for 20% of total energy requirement
• 75% of energy requirement should come from carbohydrates and protein
• Percentages of macronutrients


  • Carbohydrates - 55%
  • Protein - 20%
  • Fat - 25%
• Monounsaturated fats assist in lowering low density lipoproteins (the bad cholesterol)
• Risks of monounsaturated fats include atherosclerosis and cardiovascular disease
• Polyunsaturated fats


  Two main categories are omega 3 and omega 6
• Polyunsaturated fats act to lower LDL cholesterol in the bloodstream and increase HDL (good cholesterol), reducing the risk of cardiovascular disease
• Omega 3 fats promote the elasticity of the blood vessels and prevent blood clots
• Omega 6 fats can increase the risk of obesity and certain conditions
• Saturated & trans fats

  Contribute to high cholesterol levels in the blood, which contributes to cardiovascular disease
• Saturated fats


  • Found in foods of animal origin
  • Found in meat, full-cream milk, cream, cheese, fried foods, baked goods
• Trans fats


  • Liquid oil converted into solid fat through hydrogenation
  • Found in pies, pastries, cakes, margarines, solid spreads
• Saturated & trans fats also interfere with cell membranes and contribute to blood glucose levels
• Nutrients required during youth


  • Water
  • Calcium
  • Sodium
  • Iron
• The body is made up of 50 to 75% water
• Water


  • Forms the basis of blood, digestive juices, urine, and perspiration
  • Contained in lean muscle, fat, and bones
  • Requires a fresh supply everyday to makeup for losses in lungs, skin, urine
• Water requirement


  • Amount is dependent on body size, metabolism, weather, food, activities
  • Adult women: 2L (8 cups)
  • Adult men: 2.6L (10 cups)