Can you please suggest a supplement or whatever to help an extremely thin young teenage girl (13) to gain weight. She wants to gain weight, she has a very healthy diet, the child concerned has made it her business to gain good knowledge of nutrition and she eats well, as does the whole family. She snacks all day on carrots and other good healthy food (no junk snacks) and she eats a lot of different fresh fruits regularly, she eats large portions at meal times and there is no evidence whatever of purging after meals. She has regular comprehensive health checks and there is no evidence at all of any health issues. would appreciate your advice, thank you.