I think the serenity prayer is a good fit here....

Accept the things that I cannot change, courage to change the things I can, and wisdom to know the difference....Nobody is perfect (No-Body is perfect) and our body is something that shouldn't define us nor should we be judged (or judge ourselves) by it. The person inside this body is what is really important and all that really matters. That to me is what body positivity is all about.