- Animal fat
- Vegetable fat
All varieties of fat have an extraordinary energy content. Vegetable fats were developed by plants as a means of attracting animals in need of energy, in order to spread seeds or further pollination. In animals, fat acts as an energy reserve, and is stored in fatty tissue, normally located subcutaneously or surrounding organs. Fatty tissue consist of fat cells, designed to store energy in the form of fat.
Vegetable fat often take the form of oil, a liquid with lesser density than water. In the ancient minoan culture, and in many of the other early mediterranan cultures, olive oil was a very important commodity and at times used as a measure of wealth.
Energy is stored as fatty tissue when the nutrition/energy content of the blood remains higher than is consumed by muscular and other activity. When the energy content in the blood lessens, the fatty tissue reacts by releasing a corresponding amount of energy from the fat cells. This activity is controlled by insulin and other hormones in the body.
Both vegetable and animal fat has seen, and indeed still see, much use as lubricants, although recently various synthetic substances has taken over in most industrial applications. In cooking, products with a high fat content are often used as enhancers of taste, for example butter, milk, cheese and other dairy products. Another use of fat in cooking is as heat conductor in frying.