2-3k calories is sufficient... I was probably eating over 4,000 calories a day when I had my hunger streak... I was a freak of nature.
I remember when I went to lunch one day with a guy who is 6'4" 280 lbs. We both ate our lunch and the waitress kept bringing out chips and dip. She had to bring out 3 plates of chips before I was full... AFTER I had ate the entire entree. And btw, I was 5'4" 140 lbs. I didn't gain a pound, in fact when my appetite finally subsided, I was 128 lbs.
But it sounds like they're just worried about your nutrition and ability to keep your health in order as a human being, not necessarily because of what the hormones may do to you. Sometimes you just have to bite the bullet and do what you have to do to get to your goal. When you're 18, you can be a lil more independent and go to a different psych etc if you don't agree with the one you're seeing. However, you may need to find another place to stay if your parents don't agree with that step...
I don't miss being dependent at all.