I'm into body positivity so far as the concept means you don't have to look like a supermodel and you should just ignore societies ideal movie star body as a realistic expectation or even a desirable goal.

But that doesn't mean "let yourself go and be fat" it's all about good health, slightly fat? Not the end of the world but you should be a bit concerned about it. So fucking fat you can't walk places and it interferes with your daily life? Yeah that's a problem I think.

I'm fat but that's because I eat and drink too much. Never stopped me from climbing a mountain. If you can't walk a few miles without feeling like you've run a marathon there's a problem. If a few flights of stairs tires you out, there's a problem.

It's possible to be fat but still be pretty "healthy" all things considered. But it's usually a sign of either bad diet and or lack of exercise. If you're fat and active it's probably diet.