How many calories should my 13 year old son eat. he is 105 and 5'3.5 (5'3 1/2) he works out after school. he wants to build muscle. what should he eat?

Healthy natural food: Healthy diets have natural foods that contain fewer calories, such as carrots, celery, and iceberg lettuce. Also needed are proteins (along with healthier fats), such as nuts, beans, tofu, fish, lean meats, and a few eggs. For fruits, buy small ones no bigger than a tennis ball, because fruits have sugar. Avoid sugar, sugared drinks, or simple carbs. Do eat whole grain, higher fiber carbs.