Hi. I am a 12 year old girl, and I weigh 116.5 lbs. My thighs are 47.9cm or 18.2 inches wide. My upper arms are 29.3cm or 11.2 inches wide. I am slim, I guess, but I want to be skinny. Like very skinny. How could I lose the fat in my stomach area, lges and thigh areas and my whole arms? Baisically my whole body? Please help, I am desperate! Thank - you. :)