There are four kinds of fat: monounsaturated fat, polyunsaturated fat, saturated fat, and trans fat. Both monounsaturated fat and polyunsaturated fat are considered 'good' fat. Saturated fat is generally accepted when consumed in low amounts. Trans fat, or trans fatty acids, is the worst kind of fat. Trans fats from partial hydrogenation can cause serious health concerns such as lowering HDL, the good cholesterol, while increasing LDL, the bad cholesterol; make arteries more rigid; and cause insulin resistance. Trans fat can be found in vegetable shortenings, some margarines, crackers, cookies, snack foods, and other foods made with or fried in partially hydrogenated oils. Unlike other fats, the majority of trans fat is formed when food manufacturers turn liquid oils into solid fats like shortening and hard margarine. A small amount of trans fat is found naturally, primarily in dairy products, some meat, and other animal-based foods.