Hey, I don't know your situation, and I am sorry for your condition, but if you are anorexic, your main concern should be gaining weight at all. After your body has reached an ideal size, workout in small intervals. However, I am obviously not your trainer or anything but it only makes sense. Eat right too. Salmon has a lot of protein and protein helps build muscle consider this meal to gain wieght, and it is healthy for you: Wild Salmon, Rice, Steamed asparagus, and Fat Free Skim Milk. Also do other activities that are good for your health like deep breathing and walking. I know you didn't ask this, but also wear sunscreen. I gave you all these tips so you can not only get an ideal body, but also take care of your body. I hope I helped you.