About this time last year I was overweight (5'1" and 140 lbs) and I began a diet of 1200-1300 calories. This diet has really became my part of my lifestyle and if I eat over that many calories I now feel physically sick. But there's a problem, by sticking to this diet for a year I've gone down to 90 lbs (underweight). How can I gain 5-10 lbs and maintain it?
EDIT:I'm speaking more in calorie terms, how much should I be eating?