Fats

• Types of Fats


  • Saturated
  • Unsaturated
• Saturated fats


  • Solid at room temperature, tend to be animal sources
• Unsaturated fats


  • Liquid at room temperature, tend to be plant-based
• Degree of unsaturation


  Influences the firmness of fats at room temperature
• No double bonds = saturated fats
• Recommendations for dietary fats

  • Saturated - keep low, but do not need to eliminate
  • Less than 10% of total calories from saturated fats
  • Trans Fats - less than 1% of total calories of trans fatty acids
  • Cholesterol - as low as possible while consuming a nutritionally adequate diet
• Functions of dietary fats

  • Supply a concentrated source of energy (most energy-dense) - 9kcal/g Supply fat-soluble nutrients
  • Essential fatty acids (linoleic acid and a-linolenic acid)
  • Vitamins A, D, E, and K
  • Increase the flavour and palatability of foods
  • Contribute to satiety
  • Provide building blocks of cell membranes
  • Fats give cell membranes flexibility
  • Body fat provides protection
• Lipids


  A family of organic compounds soluble in organic solvents but not in water. Include; Triglycerides (fats and oils), Phospholipids, Sterols
• Types of Unsaturated Fatty Acids

  • Monounsaturated = one double bond
  • Polyunsaturated = two or more double bonds
• Unsaturated fatty acids


  Fatty acids with less hydrogen are unsaturated
• Saturated fatty acids


  Saturated fatty acids have the maximum hydrogen possible, solid at room temperature
• Essential Fatty Acids (EFA)


  Polyunsaturated, raw materials for eicosanoids (act like hormones), affect muscle contraction and relaxation, blood vessel dilation and constriction, blood clot formation, blood lipid regulation, immune response (includes inflammation)
• Omega 3 and 6 Fatty Acids

  • Linoleic acid = omega-6 fatty acid
  • Alpha linoleic acid = omega-3 fatty acid
  • DHA (good for growth) and EPA
• Omega-6 Fatty Acids


  Linoleic acid is an essential fatty acid from the omega-6 family, required for growth, maintenance of healthy skin, and normal functioning of the reproductive system, found in cell membranes, sources include sunflower and corn
• Omega-3 Fatty Acids


  Physiological importance of a-linolenic acid, required as a structural component of cell membranes, sources include walnuts and flaxseed
• Fat in Fish


  • Decrease the risk of heart attack
  • Decrease plaque formation in arteries
  • Decrease the incidence of high blood pressure
  • Decrease the risk of stroke
  • Protection against irregular heartbeat and sudden death
• Artificial Fats


  Trans Fats, unstable and turn rancid with time, oxygen, and heat
• Hydrogenation


  1. A process by which hydrogen is added to liquid unsaturated fats making them more saturated and solid, improves shelf life, cooking properties, and taste

  2. Hydrogenated vegetable oil has more saturated fats

  3. Hydrogenation changes the structure of the unsaturated fatty acids, converts some fats into trans fats
• Trans fatty acids


  Raise LDL blood cholesterol levels more than dietary cholesterol, saturated fats or any other type of fat, preferred for use in snacks, fried food etc because more stable and has a stronger shelf life, the nutrition facts panel must include the trans fat content
• Phospholipids


  Found in cell membranes
• Sterols


  Large complicated ring carbon molecules, cholesterol found only in animal products, tasteless, odourless, clear liquid contained in lean and fat animal products
• Cholesterol


  Found in every cell in your body (cell membranes), serves as the building block for estrogen, vitamin D, and testosterone, a major component of nerves and the brain, can not be used for energy, no evidence that cholesterol is required in the diet, the body produces enough
• Dietary Cholesterol


  Becomes HDL and LDL once absorbed in the body
• A vegan diet is 100% cholesterol-free. No such thing as being deficient in cholesterol
• HDL


  Takes cholesterol away from the cells
• LDL


  Takes cholesterol toward cells and tissues