I have a problem with my son: he is unable to gain weight past year. He was always rather skinny, but now he just stays the same weight, he is 12. He also doesn't have a great appetite. I didn't notice any negative reactions to food, but he is definitely a super picky eater. I try to offer him as much protein as possible in form of meat, yogurt, cheese. I cook him his favorite food, as there are many foods he dislikes. I don't limit his sugar intake, and I give him orange juice or chocolate milk whenever he wants. He is overall healthy, only occasionally has some sniffles, but his weight is my constant worry.