These are television shows that exploit people who have the mental illnesses which result in obesity.
You wouldn’t take a bunch of people with clinical depression and make a show called “smile, ya dipshit” about them.
Biggest loser is centered around the idea that losing weight is the answer to people’s problems when it’s not.
The one where they have these severely ill people living their lives is just so others can watch, leer, and feel quietly superior that “at least I’m not those people”.