What is wrong with me and my body?

Well before i tell you my problem i would like to tell you some facts that might help you find my answer. My name is Carl and i am 13 years old. I weight 170 pounds. I am 5"10 <<(Height.) Well about a month ago i got a physical. The doctor said i was overweight and was amazed on how strong i was for a 13 year old kid. I am currently working out twice a week at the gym, i have lacrosse games and practices. So the doctor then recommended some ""KID FIT"" program to help me lose weight and eat the right way. Now let me tell you another thing about myself, i don't eat junkfood or mive ammounts of bad food.All i eat is the right porportion and organic food. Back to the kid fit thing. Every 3 months i go in, they take my weight,my height and check up on my body. So when i was there they took a BMI (aka body m index) on me. They found out that i need to eat more ""Fatty"" foods. As i know you are saying ""WHAT??"" i feel the same way. The doctor at kid fit was "amused" on how strong and active i was and questined why i was even here. He also said i looked nothing alike to any of the other kids who do need this program. Now i don't really enjoy being "strong" as much as you may think. I was overweight to play football for 3 years so i just went to all of the practices for training. Now a couple weeks later my mom has planned out more kid fit programs for me to go to. Now i'm thinking "What the hell! the doctor said their is nothing wrong with me and i need to eat more fatty foods." But that wasn't enough for my mom (the overachiever she is :). Now she wants me to lose like 35 pounds of fat. But when i got like BMI on some 20K dollar machine it said i had to get more fatt in my body. So that means losing my mustle. <