I have suffered from an eating disorder since I was 14 (I am 21). I have always had anorexic tendencies, with occasional binge eating, but never bulimia. Twice in my life, at age 14 and 21, my weight has dropped below 92 lbs and I stopped getting my period. I assumed this was sort of my body's "set point" for losing my period. Recently, I gained weight (went from 88 to about 105 lbs, very quickly ) and I got my period back. I have been very "on schedule" since then, getting my period every 28 days exactly. I recently started losing weight again (in a healthier way, not starving myself but dieting) and working out a lot, and I now weigh about 96-97 lbs (I am 5'1). Normally, in the past, this has seemed to be an acceptable weight for my body. But.. I am now a week late for my period, which doesn't normally happen. I'm scared now that because of my past of being underweight my body has sort of upped the "set point" and now, if I want to be healthy, I will have to be above 96-97 lbs. Has anyone ever heard of this happening?
I should be clear, I know I suffer from an eating disorder, yes I have tried but failed to recover, and now I am compromising by eating more and healthier (1000-1200+ calories) but still trying to lose a bit of weight. I have succeeded at this for the past month. That is why I am so surprised that my period is messed up. In the past when this happened, I was heavily restricting and at almost exactly 92 lbs, both times.
I've also heard it may have more to do with body fat percentage than weight. I don't know what it is right now but I have been exercising a lot. Maybe that is the cause?
One week late isn't necessarily very bad. However:
1200 calories is not enough! 2000 is more reasonable! Especially if you are exercising!
I found that when I was about 20 years old, my body decided it needed more fat, and I gained about 5 pounds. Just sorta happened. A healthy weight at 14 is not a healthy weight at 21. If nothing else, your bones have more minerals and weigh more.
Also, if you are exercising a lot, you may indeed have a lot of muscle.
At your age, somewhere on your body, your belly or hips or butt or thighs should have some visible fat on them. Somewhere, you should be able to pinch at least half an inch. If not, you are too thin, and you may lose your periods.
Basically, you need to be about 15% fat, bare minimum, to be healthy. This includes the fat insulating your nerves and protecting your organs as well as the stuff under your skin. There are some online calculators that can let you estimate using a scale and a tape measure how much fat you have.