Body composition is the amount of muscle, fat, bone, cartilage etc that makes up our bodies. In terms of health, fat is the main point of interest and everything else is termed lean body tissue. The amount of fat we carry varies from person to person and healthy averages vary with gender and age. A healthy amount of fat for a man is between 15&18% and for women is higher at 20-25%. It is important to maintain a healthy percentage of body fat because: