That's because these guys have athletic heart syndrome. These guys are basically top sporters that have enlarged hearts. This is why its always bad for a top sporter to stop cold turkey with sporting. It can create massive issue's. And u can bet those obese people trying to throw eachother off a stage is top sport for their hearts, it's like a v12 engine going at full speed.
What this guy is getting is Gastric Sleeve surgery and probably isn't doing top sport.
Its typical that people lose real fast huge amount of weight because of it. Which isn't a issue. It even gets promoted by those company's. ( i think they stopped promoting it these days tho )
However what those shops don't tell you ( or didn't ), is that if you lose weight fast your skin isn't going to move with it. If you lose weight slow your skin is going to move with your body and recover for large part of being bloated. Skin is incredible especially if you are below the 30's on how it changes and shifts.
And skin will be your main fight once u lost weight. So better start taking care of it while you lose weight while u still can make a impact on it. Once its lose its lose forever.
U don't want to end up like this.
U far rather want to end up like this.
Train muscles or do muscle training 5-6 days a week after getting a easy introduction obviously towards sports, drink tons and tons of water nothing else and lose slow amounts of weight. If your skin isn't moving stop losing weight for a month or two or even three then move further.
Will take you a year or two to lose the weight instead of a few months, but its totally worth it.