I wouldn't worry - let him eat
Babies are great at regulating how much to eat and what to eat.. your job is to offer a balance of foods, his job is to decide what and how much to eat.
So long as he is still getting some milk in the way of formula or BFing, no worries. Should be 3-4 BFs at this age or if using formula, aim for no less than 20ozs per day (remembering that things like cheese/yogurt etc do count towards milk intake).