Hi there. Dietary modifications are paramount in certain present day, chronic medical illnesses require taking certain types of diets, rich in fiber, low in simple sugars and fats, multi grains, fresh fruits and green leafy vegetables to name a few. Please mention in detail the illness of your friend and repost on this forum so that it can be duly answered. I don’t see a mention of the same in this post. Take care always.
You need to let us know what illness your friend has. Then maybe someone can help you.