Try eating a healthy foods or a balance diet. Consume the right amount of nutrients per day. Try not to skip any meals. if you’re appetite is very poor, try to atleast eat small amount of food a day. Eating snacks 2 to 3 times can also help you if you do not have an appetite. Avoid eating snacks that has a Synthetic Fats in it because they don't contribute to the development of good eating habits.
I hope this helped you out.