Fat is a component both of the food ingested and of the body. Fat exists in a number of structural forms. Some types of fat can be beneficial, as an energy and an insulation source, and, in the case of fats containing high levels of omega-3 fatty acids, perhaps as an aid to retard the development of cancer. Other types of fat are detrimental to health, exemplified by the artery-clogging form of cholesterol, which can promote the damage or death of heart tissue.

There are four types of fat, based on their structure: saturated fat, monosaturated fat, polyunsaturated fat, and trans fat.

In a saturated fat, all the chemical connections between the component molecules are fully occupied. This produces fat that is hard at room temperature. Saturated fats, typically of animal origin, are the least healthy. Saturated fats can contribute to the...