The primary form of dietary fat, called triglyceride, is comprosed of two components: a "backbone" of glycerol with three fatty acids attached. Triglyceride is the fat that supplies calories in the diet and is stored in fat tissue in the body. There are three types of fatty acids: saturated, monounsaturated, and polyunsaturated. Saturated fatty acids (found primarily in meat, milk, and butter) are linked to an increased risk of developing several diseases. Health experts encourage individuals to minimize their intakes of saturated fats. Monounsaturated fatty acids are found in olive and canola oils, and moderate amounts are associated with a healthy diet. Polyunsaturated fatty acids are the only category of fatty acids that provide essential nutrients. The two types of essential fatty acids that belong to the polyunsaturated class are linoleic (omega-6) and linolenic (omega-3) fatty acids. These two classes of fatty acids must be supplied by diet. Essential fatty acids are converted to other compounds in the body. Omega-6 fatty acid is the parent substance for gamma-linolenic acid (GLA), dihomogamma linolenic acid (DGLA), and arachidonic acid. These oily substances are important for the formation of hormone-like compounds called prostaglandins. Omega-3 fatty acids, including eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), also help build prostaglandins and possibly aid in the prevention of heart disease, arthritis, and cancer.