There is a part of me that wants to respond to this with "if only I had the willpower", even though I know that's not a good response.

I used to be able to survive on very little food for months on end, but I couldn't fast, and even on little food I couldn't eat the big meal or that sugar or fat loaded splurge, as it was just too triggering for me and I'd be bingeing regularly as a normal way of life again in no time. I wished I could fast or eat very little in a compensatory way that would just even out to a small weight loss, but I could never do it.

I suppose maybe that's a blessing in disguise, even though it never felt that way.