I have a healthy weight but still having menstrual irregularities. What's wrong?

Dear Ask The Doctor: Dear Ask the Doctor, I am 20 years old and I believe that I am suffering from amenorrhea because the last time I had a regular menstrual cycle was in the end of the year 2009. I have not gotten my menses since and I have also been referred to a gynaecologist for her opinion since early 2010. I had an eating disorder when I was 14 years old. I was 60kg at my 155cm height. During that duration around half a year or so, I lost around 10-12 kg. I still had regular periods then, and when I turned 15, I almost regained all the weight I had lost. Before my 18th birthday, I again had a crash diet and lost around 13kg in 4-5 months. I was 55kg at that time and my lowest weight was 42kg. It was during that time when I realized that my period was late. It never returned to this date and the end of 2011 would mark the second year of my missing period. In 2010 and early this year, I went to another city to study so I was under lots of stress and my weight did fluctuate. My lowest weight was around 44-45kg. When I came back for my semester break in June 2011, I managed to gradually put on weight and I now weigh around 50kg. I exercise regularly (I jog for 45 minutes 4 times a week and lift weights moderately). I also practice a healthy diet and avoid fatty, sugary and processed food. I drink about 2 litres of plain water everyday. I believe that I am in a healthy weight range right now and for that reason, I am reluctant to put on weight when being pressured by my mother. I really do not want to go back to my original weight of 55kg. My gynae prescribed Duphaston for me twice so far, to be taken thrice a day for five days. I had moderate flow for four days after taking it, but I have not managed to see my menses come naturally. I had my hormone levels checked and also had a MRI scan. The doctor said there was nothing wrong with me but advised me to eat more lean red meat. Do I have iron deficiency and could this be my problem? My gynae told me to be patient and that my period will come eventually, because I had only reached my ideal weight of 50kg for only a span of 3 months or so. She explained that my body needed to re-adjust and this could take up to 6 months to 1 year. She said that I could put on a little more weight, but I am extremely reluctant to do so. I have read lots of forums online about girls like me and they usually have their periods back after putting on weight and reaching an ideal BMI. Some had their periods back even at a border-line BMI of 18.5. Will my period eventually come? Must I really put on more weight although now my BMI is already at 21? Am I doing everything right or are there some areas in which I should improve? I enjoy eating sweets and I do indulge once in a while, much to my mother's delight. I would really appreciate it if you would advice me how to go from here. I will be 21 next year and I feel so incomplete as a woman if I do not have my period. Thank you so much for taking your time to read this. Best regards, Celeste Low.

Dear Celeste: I do agree with your gynaecologist. It may take several months before your periods can get back to normal. Your BMI is just fine; however, it is noteworthy that fats are also needed to produce hormones. Women who are too athletic will have more lean muscle mass than fat; this makes fat less available to produce hormones and hormonal disturbances may ensue (e.g. amenorrhea). In your case, I commend you for maintaining a healthy weight and doing exercise. However, you may need to tone down your exercise regimen a little. Try exercising maybe 3x a week instead of 4, and also incorporate healthy fat in your diet. Having lean red meats at least 2x-3x a week is reasonable. This will probably increase your BMI to 22 or 23, which is still not bad because it is within the normal range. I also think the eating disorder you had a few years ago is significantly responsible for the hormonal disturbances you are having right now. Try and be more patient; you can also reduce your stress level and have slight modifications (as previously mentioned) in your diet. I do hope this helps and take care always.