BMI is stupid, but that doesn't mean you can be as fat as you want. The government wants the average man to weigh like 135 lbs which is not even good. That's slight but not strong.

I thought it was just wrong for body builders, but they really want everyone to be weak.

Still if you're getting to 200 you would have to be really really buff to be healthy. But that's not even what most people mean when talking about obese. I would say well over 200 at 5'8 or whatever avg height is where most people start to see obese, and obviously a lot of people weigh more than that.