Roles of fats in the body: cell structure cell membranes, fuel and energy storage 9kcal/g, long term storage, hormones steroids, testosterone, protection cushions internal organs, thermoregulation provides heat, transportation lipoproteins, fat soluble vitamins. Alpha linolenic (apa) and linolenic (la) acids are essential fatty acids. Ala (18:3 omega-3) serves as a precursor for eicoapentaenoic acid (epa . 20:5, n-3) and docosahexaenoic acid (dha 22:6, n-3) hufas (highly unsaturated fatty acids) La (18:2 omega-6) undergoes elongation and desaturation to form arachidonic acid (20:4, n-6) The pathway from one omega-6 fatty acid to another. Linoleic acid al 1. 6g males, 1. 1g females. Now ~ 5% and 0. 5% in canada. Average north american diet provides ~31-35% of energy as fat. Dri keep low or low as possible . It is the position of the ada and dc that dietary fat for the adult population should emphasize a reduction in sfa and trans fatty acids and an increase in n-3 pufas .