Hi, I'm 20 and I'm 5'4" and weight currently 115. In high school I was a lot lighter, I can remember starting high school being about 5'2" and weighing a little over 80 lbs. I was so active that I was mostly muscle and zero fat, but when I got to college I went from 100 lbs, to 114 in the first two weeks of school (thanks freshman 15!!!) and have been able to keep my weight up that way. Also birth-control helped me put on some weight.