Most people are surprised to learn that fat has some virtues. Only when people eat either too much or too little fat does ill health follow. It is true, though, that in our society of abundance, people are likely to encounter too much fat. Fat is actually a subset of the class of nutrients known as lipids, but the term “fat” is often used to refer to all the lipids. The lipid family includes triglycerides (fats and oils), phospholipids, and sterols, all important to nutrition. The triglycerides provide the body with a continuous fuel supply, keep it warm, and protect it from mechanical shock; their component fatty acids serve as starting materials for important hormonal regulators. The phospholipids and sterols contribute to the cells’ structures, and the sterol cholesterol serves as the raw material for some hormones, vitamin D, and bile. In foods, triglycerides are the solid fats and liquid oils. The triglycerides carry with them the four fat-soluble vitamins – A, D, E, and K – together with many of the compounds that give foods their flavour, texture, and palatability. Fat is responsible for the delicious aromas associated with sizzling meat and hamburgers on the grill, onions being sautéed, or vegetables in a stir-fry. Of course, these wonderful characteristics lure people into eating too much from time to time.