Hi and welcome to our forum!Compare your fatty tissue and overlying skin to an air-filled balloon. As you partially deflate a balloon, the rubbery skin contracts, maintaining the balloon's shape. If you deflate further, the rubbery skin of the balloon will wrinkle, and finally there will be balloon shape collapse. As one removes fat from under the skin, the rubbery skin will contract, maintaining its integrity. With continued fat removal, a point will be reached where the skin collapses and wrinkles. This is more likely to occur if there has been previous skin damage, such as the presence of stretch marks. Stretch marks indicate the presence of permanently damaged overstretched skin usually occurring during pregnancy or significant weight fluctuation where when pregnant or heavy, the skin's dermal elastic fibers rupture, resulting in the loss of elasticity and the development of streaks on the skin surface. The skin will stretch over a greater surface area and will predispose to sagging. A skin tightening procedure may be required.Best wishes...