to be fair, part of the reason people want excuses and don't love themselves enough to make a change is that being fat is treated as fucking awful, even if you're only a bit overweight. the reaction isn't 'oh, you're about 10-20 pounds overweight, you should cut back on sweets and snacking,' the reaction is 'you have to change your entire lifestyle and also you're fucking pathetic for letting it get this far.'

so people backslide, because they're being told they're already 'ruined,' and that losing weight will be the most insanely herculean task ever, so things get worse, until eventually losing weight - and getting out of that mindset - really is incredibly difficult.