I will try to offer some suggestions. Be sure he is taking a good multivitamin supplement. Have him eat a good breakfast before he takes his meds at a time when his appitite should be pretty good. How about making milkshakes for him if he likes those. Those can have all kinds of nutritious ingredients in them or just be plain but contain a good number of calories and kids tend to like those even if they are not real hungry since it is something they can sip on. Keep a supply of his favorite foods in the house to try to encourage him to eat. Does he like things like yogart? Those sometimes might be appealing enough that he would eat them as they are smaller plus some of the new ones you can just squeeze and eat. Plan your meals around high calorie nutritious foods at so that what he does eat has enough calories to sustain his weight. Remember part of the reason for the weight loss is the fact that he is not taking in enough calories to maintain his weight so you need to think terms just the opposite of a dieter. Instead of looking for low cal nutritious foods you will want to look for high cal nutritious foods. If your son is not eating good at lunch time at school try some of these things. Send a sack lunch but send things he really likes such as cottage cheese in a thermos or mini suasage snack sticks. If they have access to a microwave at lunch how about Lipton brand "cup a soup"? My son enjoyed taking that and making soup for lunch (until they took out the micro at his school). You can be creative with his sandwiches depending on his age by using cookies cutters to cut his sandwhich meat and bread into need shapes. If he likes things like "SpaghettiO's" then heat those in your micro and send them in a thermos along with a plastic diposable spoon. If all else fails you can also ask your doctor for a referral to a dietician for suggestions. I wish you luck as I have been down that familiar path before with my own son. Hopefully at least one of these suggestions will be of some help.