Hi, I know this seems a bit strange, but my 3 year old has always been underweight (not severley), but always on the low percentile lines, and whenever he's ill with bugs, which isn't very often, but when he is he drops weight very quickly. He eats what I consider to be quite a lot, and good foods with good fats, such as peanut butter, avacado, full fat milk, cheese and those sorts of things but he just never seems to gain weight. I think he takes after my sister and her little girl is the same. Is there anything that I can give him that would help him gain a bit or bulk him up a little bit. I am thinking like a tonic or something like that.
Thanks for any advice.