I have a classmate who weighed more than 200 kilograms when he was fattest. Then he wants to lose weight, so he insists on running every day to lose weight. After nearly two years, he lost weight completely. His thinness is that kind of health, not that he has a lot of skin. So, I think if you lose weight normally and exercise every day, you won't have these fat skins at all. On the contrary, you may become muscular by losing weight.
Of course, I also know a girl who wanted to lose weight quickly and had liposuction. Then, although the fat and oil in the stomach were taken away, there was still a lot of fat on the stomach. No matter how ugly you say, she is still ugly even if she wears clothes. She said that she knew from the beginning that liposuction would not be done, which was not as good as when she was fat, but it was not so good.
For a girl with 20 kg of fat skin, I feel that the best way is to have a facelift, which will be beneficial to their beautiful figure. And I want to warn those friends who want to lose weight quickly and have liposuction surgery, that is, they must understand, otherwise, you will regret leaving a fat skin.