Underweight again?

Hi! I've pretty much been underweight all my life. When I was a little kid, up until maybe I was 12-13, I was always in the "5th percentile" for BMI. Once I hit middle school, I became very inactive, and gained weight and body fat. I wasn't overweight, though, just not in shape. But, once I got into high school, I joined the track team in the spring, and my weight went down from 107 lbs. to 94.5 lbs. minimum. (I weight myself on Wii Fit, and I usually use "Light" for my clothing weight measurement.) It says that my BMI is around 16.4 or .7 or something, and that's underweight, but I eat my recommended calorie intake (2000-2200) everyday, and I rarely eat junk food! I don't have the smallest body frame in the world (genetics of being Norwegian AND Italian), but I think my metabolism has a big part to play, since I exercise almost everyday now (6 days minimum.) I was wondering if I should actually work on gaining more weight, but how much so I don't become unhealthy, since I relaly enjoy being physically fit now (I can run so much faster at track meets!). Sorry this was such a long post! :(

EDIT: I guess I should mention why I was always so small as a little kid. Basically, I never sat still. I was always up and running around, playing and having fun. I was an outdoors nut (before I got my first Gameboy, haha), and my metabolism was like lightning (I cloud eat 2 slices of cake for a week everyday and LOSE weight.) So, yeah, there you go. :P

The part you're getting wrong in the story was that your recommended calorie intake is 2000-2200.   That would be OK for a healthy-weight teenager that didn't exercise much.... when you exercise you use up energy and you need to replace that energy with food.   It's going to be 3000 minimum for you to start gaining weight .... possibly higher.  (BTW. Cake is just food like anything else... ) 

People can be naturally thin but once your BMI drops below 18.5 you're medically at risk.  Sub 17 and you're in very, very dangerous territory indeed and you have to start taking it seriously.   (I know your parents are already worried about you because you've said so in other posts.)  You shouldn't be doing vigorous exercise, for example, because your heart muscles may not be strong enough to withstand the effort.  Your heart could quite simply give up on you any second.... and that would be it.    Do you still get periods or have you ever had periods?  One of the first signs of a female body being unhealthy is when periods cease.

Whatever you do, please go to see your doctor for some physical checks and qualified advice.  It is quite possible to get 2000 cals a day and to still have an eating disorder...

having a BMI of 16.4 does not happen so i would think you are restricting. eat the 2200-2500. its not rocket science. a calorie is a calorie, i eat cake most days of the week and can lose weight. your metabolism aint lightning

You need to be eating about 3500 calories to gain if you insist on doing track. Otherwise I think you need to stop the track pronto. Your weight is dangerously low enough to possibly cause you a heart attack. If your parents are worried they should likely be a little more involved in this. Tell them you're going to need probably around 3500 calories - perhaps let them cook or prepare your main meals. I suggest you also talk to a doctor. Immediately.

Many normal weight young people in sports like track need a very high calorie diet. You mentioned you feel you run faster right now but being underweight you are at very high risk of injuries or other complications. I used to run when I was underweight as a teen and it ended me up in a cardiac unit. You are loosing weight too and that is a sign you are not eating enough when you were underweight to begin with. The fact is regardless of what calorie counters say you are not eating enough. Inpatient many young people eat 4000 plus calories doing nothing. No calorie calculator would state this for someone because it is not taking into account the high needs of refeeding. Please take care