Lipids, or fats, are substances that do not dissolve in water, and are necessary for survival. Currently, the USDA recommends 20% – 35% of calories should come from lipids. We need this amount of fat for things like the maintenance of cellular membranes, which are made from lipids.
Lipids are also a high-density energy source and help us absorb fat-soluble vitamins. In addition, lipids cushion organs and insulate the body. Finally, they provide raw materials for vitamin D and hormones, as well as give taste, consistency, and stability to foods and make us feel full after eating.
Lipids are found in meat, poultry, nuts, milk products, butters and margarines, oils, lard, fish, grain products, and salad dressings. There are three main types of fat: saturated fat, unsaturated fat, and trans fat.