Expert: Ryan Hale - 12/8/2009

Question
Hi, I'm 16 and am currently trying to fix my metabolism after slowing it significantly from losing quite a bit of weight. I'm about 5'5 and during the period of last nov to aug went from 112lbs to about 95lbs. Then when parents/professionals etc. noticed, I had to gain the weight back and am now about back to what I was at the start.   

I got down to eating about 300 -400cal a day at my lowest, gradually decreasing to this amount. When I was initally made to regain the weight I think my metabolism went into hypermetabolism because I needed about 2500 to gain about 800g a week. When I left the clinic I was in at 108lbs I immediately cut down my intake to about a quarter unfortunately - to about 700cal . I think this absolutely halted my metabolism so in the following couple of weeks when I ate about 1000cal I gained quite quickly.  

Now I just want to return my metabolism to normal without gaining anymore because I have reached my set weight I think now. I want to be able to eat about 1500-1700 and just maintain. Oh and I'm not meant to exercise so that won't really help.  

Also could you help me relate the 'set point' idea to my situation. I mean I thought 112lbs was mine because I had maintained that weight for years with little effort or thought. Now however I am being told I need to be much more, like 121bs. Does this mean that my set point is altered? Is there any way I can return my metabolism to normal whilst staying at 112lbs?

Oh and also I have never had a period, its believed that ive had too low a weight for a few years in  combination with a low fat diet. How long do you this it would take for my period to return approximately once I reach the necessary weight? How much is having your period based on your weight/amount of fats in your diet?
 
Thanks in advance  

Answer
Sophie- having an eating disorder and trying to maintain a very low weight can be the cause of your menstrual cycle being altered or not starting at all if it is done at the point in your adolescents when you would normally begin.  The earlier and younger you start and the longer you have that situation, the more difficulty you can have setting your body's metabolic point later.  It can take a really long time to get back to a "set" point.  You also have to eat the amount of calories needed for your body to get out of "starvation" mode.  Your body can sense when you aren't eating enough and as a survival mechanism, it says to itself "we had better not bring a baby into such hard times," so it stops your menstrual cycle to prevent that.  For some women it is very very low, for others a little emotional stress from school or work and loosing a few pounds can do it.  Every woman is different.  Take body builder women.  They are very lean and diet extensively during competition time.  Some will lose their period right away while others will not be effected that much.  It's impossible to say.

Maintain an healthy weight and diet and eventually, your body will return to "normal."