@lah Try doing Ensure to get needed nutrients into him. Keeping up your body is important. Another thing is to try things like Slimfast type powders, or protein powders, making up milkshake type drinks with ice cream, blended fruit [bananas, strawberries, etc] or flavorings to make it palatable. Also, check with his doctor and local support groups, for any tips they can offer. I hope this helps.
Ginger