The scientific term for body fat is "adipose tissue." Adipose tissue serves a number of important functions. Its primary purpose is to store lipids from which the body creates energy. In addition, it secretes a number of important hormones, and provides the body with some cushioning as well as insulation. Body fat includes essential body fat and storage body fat.

Essential body fat is a base level of fat that is found in most parts of the body. It is necessary fat that maintains life and reproductive functions. While having excess body fat can have many detrimental effects on a person's health, insufficient body fat can have negative health effects of its own.

Storage fat is fat that accumulates in adipose tissue, be it subcutaneous fat (deep under the dermis and wrapped around vital organs) or visceral fat (fat located inside the abdominal cavity, between organs), and references to body fat typically refer to this type of fat. While some storage fat is ideal, excess amounts of storage fat can have serious negative health implications. The rate at which body fat accumulates is different from person to person and is dependent on many factors including genetic factors as well as behavioral factors such as lack of exercise and excessive food intake. Due to varying factors, it can be more difficult for certain people to reduce body fat stored in the abdominal region. However, managing diet and exercise has been shown to reduce stored fat.