i USED to weight 150 lbs when i was 13 years old, then i decided to take action and lose weight. and i did just that I lost 20 lbs in about 1 month. and there was slight stretch marks, but a year later i lost 10 more pounds ALONG with LOTS of tennis, but there still was a little looseness in my lower tummy. However, within the next yr. with continued exercise and small amounts of food it was gone. BUT ITS BACK LOL.