My son is 13 and lives with his mother. will avoid eating at meal times and wants snacks only. he is too thin. could this be an eating disorder?

Hard to say: Without knowing the full details of how he eats in both places. When he is with you, try having meals together sitting down. Make the meal a zone of discussion rather than a battleground. Teens often make poor choices when eating. Living in two households with different rules can make this a challenge. Dialogue with his mom if you can.

Eating Disorder: Not necessarily, if you have any doubt have him examined by your pediatrician to make sure he is getting sufficient nutrients. Try introducing him to shakes, smoothies with protein. The sweet taste of the fruit often appeals to young people. Best wishes.