Do all recovering anorexics go into a hypermetabolic state? If so why am I not?

So here's the deal. I went to the hospital to recover from anorexia and I worked up to eating 2500-2800 calories a day and when I got him after 10 days there I relapsed eating only 1300. My worry is that because of that and now being on more calories again my body will never go into a hypermetabolic state. Am I right to worry or will it happen?