I have a very good friend. She is very nice and we have much in common. But we have a clear-cut distinction in the physical plan.
She is very skinny and it is very hard for her to gain weight. It is her problem from the childhood. When she was a little girl, she heard all the time that she was so skinny and that she should eat this and should eat that. And she once met a person who told her that, she was so skinny that she would never be able to carry a baby. She ended up going to the doctor and he told her that it was a stupid thing for anyone to say. But she was so paranoid about her weight that she went on a get fat diet.
I am positive that to find the best solution for such situation is to find the perfect mentor.