My bipolar cycles directly affect the amount and quality of food I eat. It doesn't affect my weight though, my body seems to be allergic to fat.

When hympomania hits, I will binge like its going out of fashion. I'm perpetually hungry and crave "heavy" food, mostly junk food. I eat until I roll over and 2 hrs later I do it all again. I would eat the furniture if I thought it tasted like pizza.

When I'm depro, I forget to eat. Once I nearly fainted and was very confused as to why because I'm not the fainting typ. lol it was because it was my 3rd day sans food. That's the extent of no appetite and forgetting to eat I experience.

Maybe its your pms, maybe its your mood, maybe its a med, as mentioned above record it and see if you find any correlations. If I were you I would worry more about the feelings and thoughts (eg. Guilt) that accompany the eating as you have a history of ED and may need to address those.