Welcome to health care magic forum.
the diet plan
for ur kid would be like any adult that is frequent meal pattern at regular intervals. you can give your child food/snacks/fruits every 2-3 hourly. the quantity of food depends on his appetite. u must try n involve all seasonal fruits and vegetables for ur child in his diet.
Also it would be easy to discuss with ur child about his likes n dislike and plan the menu beforehand so that there is no wastage :-)
along with all the foods and nutritious food u need to keep ur child active by involving him in some games or activities.