It is not any kind of rebellion to be fat and unhealthy (which, yes, statistically do go hand in hand) because some men prefer you’d be lithe and limber.

That’s only rebelling against yourself, which isn’t that useful.

Being fat and unhealthy is its own punishment, on many axes. Your life will be more uncomfortable and difficult. You’ll tend to be a burden both literal and metaphorical on others. And you’ll die earlier.

Corpulence to spite some ill-perceived expectation from others is roughly equivalent to gouging your own eyes out when you see something on TV that you don’t like.

Reason, though, is the last thing people try and only when all other approaches have failed. This is no different.