I'd go steady with fasting and keep a really honest eye on your reaction to it. I started doing intermittent fasting and 5:2 in November last year, the initial results were amazing, the day after a reduced calorie day I felt better than usual and I really thought I had hit on something. It was also helping me reduce some of the extra weight I'd put on with ME. The benefits were short-lived but I pushed on with it, even though I wasn't noticing the initial improvement in symptoms and energy levels. I kept going because I was so hung up on what the bathroom scales were saying! If I'd been honest with myself, I would have admitted that by December I was no longer getting the improvements in symptoms and energy and that my overall ME picture was deteriorating. I had a massive flare/crash a few weeks ago, where I was bedbound again for the first time in months. I don't believe this was caused solely by the fasting, I'd also had some unexpected demands on my mental and physical energy, but when I took some time to take stock and reflect on the last few months I realised that the fasting had probably not been helping. This is just one person's experience, though. I believe fasting is a great tool on many levels when a person is healthy, but it didn't fit with having ME in my case.