Friends and family could help by researching and learning more about this struggle. They can find out things they can do like any exercises, special foods, or medicines that can help. Overall just being there for the persona and always supporting them is a great mental help as well. Try not to treat that person so differently because that could offend them. These are just my thoughts. Otherwise, just help them maintain a strict diet of certain foods.
And you and that person should never loose hope. It gets better if you let it! :)
