Extremely loose and flabby abdominal skin and muscle can form in the lower abdomen, usually following massive weight gain and immediate loss, or multiple pregnancies. Abdominoplasty, which consists of the surgical removal of this tissue, is helpful when diet and exercise have not corrected severe muscle weakness (which may occur after multiple pregnancies); or when the skin and muscle cannot regain its normal tone (which can occur with massive obesity in young people and slight obesity in older people). Abdominoplasty is not used as a substitute for weight reduction.