A tummy tuck, like liposuction, is a body contouring procedure that can make a permanent change in body shape but not necessarily weight. The 3 reasons to have a tummy tuck are loose skin after pregnancy or weight loss, muscle separation (called a diastasis) that is common after pregnancy, and localized fat that is out of proportion to the body as a whole. When fat accululates in particular areas, and doesn't reduce with diet and exercise as quickly as in other areas, then a permanent change can be achieved by removing fat cell either with liposuction or tummy tuck. However, sometimes internal body fat can increase, but this generally responds better to exercise.