When my sons played basketball the coach preached PASTA for every meal. We had a lot of spaghetti, lasagna, alfredo, and macaroni and cheese, with added meat for protein.
Your son should not be on a diet, but learn to eat the right thing to give him strength to do his job as a basketball player. Carbs are a great way to build up strength. Go to the internet and look up good carbs and use that list. Easting the right food is his best bet.
