How many calories should a female teenager eat and lose per day.?

You cannot cut calories below your height/weight requirements, otherwise your body will store the small amount of calories you take in into your fat cells, and remove the necessary nutrients from your body. Counterproductive because you will gain weight and atrophy. Calculate your height and age into the below sites and go from there. If you starve yourself without the proper nutrition, you won't loose weight, you'll just sacrifice health and gain weight.