Fat is one part of the human energy expenditure and contributes 80% of the daily energy needed to sustain growth and maintenance of the body. It also stores a third to half of the energy necessary to maintain bodily functions such as respiration, urination and defecation, as well as essential hormones such as cortisol and testosterone which, when consumed in excess, contribute to the development of obesity and diabetes in humans and animals.
While the role of fat in energy expenditure is well known, its relation to body weight is still not completely understood. For this reason, most weight loss programs have not been able to show how fat can affect body weight. But recent research has been revealing some important information about fat distribution in the body, and the contribution it plays to maintaining weight loss.
First of all, fat is stored in an unusual configuration called the fat mass. However, there’s no way you could be aware of the actual proportions and positions of fat mass in your body if you were not trying to be on the healthy weight spectrum.
Fat is concentrated in three major muscle groups — the thigh – the abdominal – and the liver – called the adipose tissue.
Fat mass and body fat
One third of the fat-mass lies in the legs. That percentage may be even higher if you consider the size of your hips and other hip-shaped muscles as well. However, it is not possible to know precisely what percentage of mass lies in the legs since it depends greatly on the position and muscle groups in the body.
The body fat distribution in the upper mid-section mainly consists of fat tissue in the abdomen, the thighs and the neck as well as the belly. This is more than 70% of fat mass in this area and accounts for approximately 50% of its total weight.
However, the proportion of fat in the thighs or hips in relation to that in the body mass can be less than that, since those parts are also very underdeveloped with regards to skeletal muscle. This area is usually referred to as ‘buttock fat’.
Fat in the liver is less noticeable and only 3% of fat mass lies in this site. When the liver is weighed on a scale the fat lies on its surface. However, in some organs such as the stomach, which is generally a larger percentage of body mass than that in the legs, the fat is generally concentrated in the lower part of the body where muscle will contribute less weight than the fat in the mid-section of the liver.