At 21 years old I have stretch marks is my skin ?

U should b fine..make sure to saturate ure skin with coco butter religiously like 3 x a day while dropping 40lbs. U will most likely have a little flab, but maybe not. Its dependant on how quickly u drop weight. A Gradual loss is ideal to avoid flab and reduce severity of stretch marks. If lotions and creams fail to work there's always plastic surgery. Lastly ure very young and its understandable that u want to look top knotch, but if ure thinking that stretch marks and a lil flab will deter men think again. Real men don't care bout that I promise. If u find one that does then stop messing with that lame. Hope this helps