Grieving the ideal body goes beyond the body itself.

How about grieving your quality of life and longevity instead, since you're bound and determined to destroy both?

Letting go of the ideal body forces you to look at other areas of your life you thought you could control if you could 'just' work hard enough, care enough, be motivated enough to get this ideal body.

So what? You're going to start treating your job, your relationships, your education in the same shitty way you treat your body? Hey, why not? If you won't take care of the thing that is central to you thriving in other areas of your life, why bother caring for the externals?