I feel your pain. When I was first recovering from anorexia I had to basically inhale everything due to developing hypermetabolism https://www.scienceofeds.org/2014/05/07/hypermetabolism-in-anorexia-nervosa/  Hypermetabolism is hell. You get night sweats, stomach problems, can't regulate body temperature, and feel like shit all the time. Annnd, no matter how shit you feel, you stil have to eat or you'll lose weight because your body doesn't know how to properly process this new energy. Upset stomach? Not hungry? Tough. I'm so glad that crap is over.  What really gets me is that, a few time, I've seen fats JEALOUS of people with hypermetabolism or other conditions that make the body unable to properly store energy. It is unfathomable to hams that some people DON'T want to eat all day.