Question: how can a 10 year old boy gain weight?
Answer: Try eating 6 to 8 smaller meals or snacks per day. If you can only eat a few bites, eat more often, every half hour if needed. Avoid favorite foods when you feel nauseated, or sick to your stomach. ...  Save favorite foods for when you feel good! Eat when you feel hungry. ...  Don't fill up on liquids at meals.