Give them to him earlier when he is 'really' hungry. Kids often have a hungry window of opportunity in the afternoon between 3 -4.30 (this happens to be the time of day when we best absorb nutrients!) feed them veggies and rice then, and then part of the family meal when you eat later on. Also juicing veggies for a mid morning snack, carrots, beetroot, spinach, parsley and some fruit to sweeten it, kids love it and it's a nice boost before lunch.

Make sure you are not missing his hungry period and filling him with snacks trying to stretch him to dinner.