How do gain some pounds when having fast metabolism?

well I'm 16 and I'm 92 pounds, my doctor says I'm fine but everyone else thinks I'm too skinny. i wanna gain some pounds like my arms are so skinny and i don't know ho to gain pounds because i have fast metabolism. i want to be at least 110 i don't like when people ooh you don't eat? like i hate that so any ideas please