Since you're 16, as long as you avoid sugary foods or ones laden with too many simple carbs, stay active and you'll be fine. It really depends on your height and level of activity to determine the amount of calories you need every day, but there are calculators that you can find on the internet for those types of calculations. E.G.: I'm close to 5'10" and 165lbs, in order for me to lose about 1-2 lbs a week I need to restrict my diet to 1200ish calories, and to gain 1-2 lbs a week I need to eat close to 2000 calories per day, at 1500-1600 net calories per day I'll stay at the same weight each week.
If you feel you are at a comfortable weight now, then figure out your calculations and allow yourself to gain and lose a few lbs each month, and it should help with the fat redistribution while on HRT. Stay healthy and active, and HRT will do amazing things for you since you're starting so early.