Hi, I don't know for sure… but it could be part of what you're experiencing physiologically in the beginning is similar to the boost in energy one feels while fasting intermittently. There are other explanations for this, psychologically as well. However it is generally not thought of as an overly safe practice for someone suffering from such an eating disorder. That said, have you identified the root cause of your anorexia? For sometimes that will help solve some of their problems in this regard. If they can focus in on, and work towards correcting the why of their eating disorder. Lots of times professionals can aid or assist in this. Now while I don't know what you're going through. It seems as though it may be a little of a case of opposite ends of the extremes, and the battles that can take place in those. So what you might try to do, is to come up with a more balanced meal plan. So as to not over-stress, or exacerbate one end of the extreme or the other. How you do this could be helpful if control was in part at the heart of the issue. Obviously, the better you eat (as in healthier) the better… what you're also doing as you come out of these periods of fasting, or not eating, is breaking them with a binge. And that's a huge no-no, for anybody. Anorexic or not. And it explains greatly why your body is reacting with those negative symptoms or side effects. It is better to ease your way back into things slowly. And gradually. That said it can be hard to do while the mind is on overdrive and thinking about food all the time. Again although not recommended, if it is simply too challenging or too difficult for you to eat more balanced schedule of meals. You may want to devise a strategy of some type of intermittent fast, that will be less demanding and taxing on your body now. And therefore less apt to push you through to the binging end of the cycle or phase once it's all over and done. There's a bunch of them, and it all comes down to what you think might work best for you, both physically and mentally, in terms of what you're able to best tackle and then to give yourself your best chance at success going forward and ahead into the future. Good luck!