Learn what dietary fats do for the body and how much fat is recommended per day. Look up how much fat is in popular foods, like avocados and eggs. In nutrition, biology, and chemistry, fat usually means any ester of fatty acids, or a mixture of such compounds, most commonly those that occur in living beings or in food.

Contrary to past dietary advice promoting low-fat diets, newer research shows that healthy fats are necessary and beneficial for health. In mammals, fat, or adipose tissue, is deposited beneath the skin and around the internal organs, where it also protects and insulates against heat loss. Fat is a necessary, efficient source of energy.