Same to my condition, I'm 15 years old, 39 kg and 22 inch of waist. My family had just of normal weights and sizes. It just started when my friends called me as fat or chubby just because I wear huge clothes. I have fear in eating rice so when my mom puts on a meal, I pretend to eat and put the piece inside my mouth, then later on I'll took it out and throw it. Cycles just move on. I also workout and skip meals to just prove I can wear any garments. How can I overcome this without gaining weight?