Triglycerides are the chemical form in which most fat exists in food as well as in the body. They belong to a larger group of compounds called the acylglycerols or glycerides, which are esters of saturated or unsaturated fatty acids with glycerol. Mono- and diacylglycerols usually only occur as metabolic intermediates, whereas the triacylglycerols, or triglycerides, are neutral fats.

Fat molecules are generally made up of four parts: a molecule of glycerol and three molecules of fatty acids. Each fatty acid consists of a hydrocarbon chain with a carboxyl group at one end. The glycerol molecule has three hydroxyl groups, each able to interact with the carboxyl group of a fatty acid. Removal of a water molecule at each of the three positions forms a triglyceride. The three fatty acids in a single fat molecule may be all alike or they may be different. They may contain as...