Remember there are two different types of fat. Visceral fat, which is internal fat that lies over abdominal organs. Visceral fat is lost through diet, exercise and lifestyle modification. Fat to be removed and sculpted is subcutaneous fat that lies over muscles and tendons. Subcutaneous fat is due in part to genetics and gender (male vs female). It responds well to shaping. So the simple answer, is yes, you can gain weight if you’re not careful and make poor lifestyle choices.