Fats

• Fat


  Macronutrient that supplies the body with energy
• Oils


  Fats that are liquid at room temperature
• Fatty acids


  Parts of a fat molecule
• Triglyceride


  Fat molecule
• Monosaturated fatty acid


  Fatty acids found in solid fats and liquid oils
• Saturated fatty acids


  Fatty acids found mainly in solid fats
• Unsaturated fatty acids


  Fatty acids found mainly in liquid oils
• Visible fats


  Fats in a food that you can see (e.g. fat on meat)
• Invisible fats


  Fats in a food that you cannot see (e.g. butter in pastry)
• What is fat?


  Fat is a macronutrient that is needed by all animals.

  Fats are solid at room temperature.

  Fats are called oils when they are liquid at room temperature.

  Fats and oils have the same basic chemical structure and provide the same amount of energy (9kcals/37kJ per gram)
• Chemical structure of fats
• Fat molecules


  Made of one unit of glycerol and three fatty acids
• Triglyceride


  The molecule formed by one unit of glycerol and three fatty acids
• Types of fatty acids

  • Saturated
  • Unsaturated (mono saturated
  • polyunsaturated)
• Saturated fats


  • Foods with a lot of saturated fatty acids
• Unsaturated fats


  • Foods with a lot of unsaturated fatty acids
• Solid vegetable fat spreads can be made from liquid vegetable oils
• Essential fatty acids


  When we eat foods containing fat, our body breaks up (digests) the fat molecules they contain and makes new fatty acids and fat molecules specifically for our body to use. Two fatty acids cannot be made in the body and have to come ready-made from the food we eat. These are called essential fatty acids and are needed by adults and children. They are mainly found in oily fish, plant and seed oils, eggs and fresh meat
• Functions of fat in the body

  Fat has four main functions in the body:

  1. To provide a store of energy in the adipose tissue under the skin
  2. To insulate the body from the cold and help it to stay warm
  3. To protect bones and the kidneys from damage by providing them with a protective cushion of fat
  4. To give the body fat soluble vitamins A, D, E and K
• Main sources of fat in the diet

  • Visible fats
  • Invisible fats
• Fat


  Nutritional aspect referred to as just ‘fat’
• Lipid


  Another term used to refer to fat
• Visible fats and oils

  Fats and oils that are easy to see (e.g. fat on meat, oil in tuna)
• Invisible fats


  Fats that are difficult to see because they are combined with other ingredients
• Types of fat


  • Solid animal fats
  • Solid plant fats
• Solid animal fats


  • Main sources - Visible animal fats: butter
  • lard
  • suet
  • ghee
  • fat on meat
  • food containing invisible animal fats: cheese
  • butter in cakes
  • biscuits and pastries
  • meat products (e.g. sausages
  • corned beef
  • salami)
  • meat (in between muscle cells)
  • many processed ready meals and take-away foods
• Solid plant fats


  • Main sources - Visible plant fats: white vegetable fats
  • vegetable fat spreads (old name = margarines)
  • coconut cream
  • cocoa butter
  • foods containing invisible plant fats: many processed foods (ready-made curries
  • ready-meals and fast foods that have been fried in hydrogenated vegetable fat)
  • e.g. fried chicken
  • fish and chips
  • chocolate (including white chocolate)
  • pastries
  • cakes
  • biscuits
  • doughnuts and breads made with hydrogenated white vegetable fats and vegetable fat spreads
• Types of fat


  • Liquid animal oils
  • Liquid plant oils
• Liquid animal oils


  • Main sources - visible animal oils: cod liver oil
  • Oily fish (e.g. mackerel, sardines)
  • Foods containing invisible animal oils: milk
  • cream
  • egg yolk
  • oily fish (e.g. sardines, salmon, herring)
• Liquid plant oils


  • Main sources - visible plant oils: nut and seed oils (e.g. sunflower, rapeseed, sesame, corn, olive, almond)
  • Foods containing invisible plant oils: seeds (e.g. pumpkin, sunflower, sesame, groundnuts (peanuts))
  • nuts (e.g. walnuts, almonds, pecans, cashews)
  • fruits (e.g. olives, avocado pears)
  • vegetable fat spreads
  • blended butter spreads
  • fried foods (e.g. doughnuts, chips, chicken nuggets)
  • many processed foods
  • ready-meals and take-away foods (e.g. curries, ice cream, salad dressings, sauces, dips such as hummus)
• A deficiency of fat in the diet is rare in the UK
• If carbohydrate intake is also reduced


  Body weight will be lost
• The body will use the store of energy from the fat cells and it will not be replaced
• The body will chill quickly due to insufficient fat to insulate from the cold
• The body will bruise easily and the bones will hurt if they are knocked due to insufficient cushion of fat (adipose tissue)
• Insufficient fat can prevent damage to blood vessels and bones
• The body will not receive enough vitamins A, D, E or K due to lack of fat in the diet
• Vitamins A, D, E, and K are found in foods that contain fat
• Effects of an excess of fat in the diet

  . Fat provides the body with energy (9kcals/37kJ per gram)

  . Foods that contain fat are therefore energy dense

  . If the energy from fat eaten in foods every day is not all used in physical activity, it will be sorted by the body under the skin in adipose tissue and elsewhere in the body (e.g. around the intestines (visceral fat)). Consequently, the body will gain weight and could become obese

  . Eating a lot of foods that contain high levels of saturated fatty acids has been linked to the development of coronary heart disease (CHD) in some people
• Amount of fat needed every day for different life stages

  The amount of fat we need is calculated as a percentage of our total daily energy intake, rather than by weight. This is the amount of fat recommended by health experts for different groups of (healthy) adults every day:

  Total fat - no more than 35%

  Saturated fatty acids - 11%

  Monosaturated fatty acids - 13%

  Polyunsaturated fatty acids - 6.5%

  Trans fatty acids - no more than 2%