Mathew probably needs less calories than other students since he is not as active. The calories he takes in need to be very nutrient-dense so that he gets all the vitamins and minerals he needs to keep his bones and muscles strong. The best foods for him would be fruits, vegetables, skim milk, whole grains and small amounts of meat. Some kids are so hungry before lunch that they do not have any energy. Lunch gives them food for energy plus the social interaction usually makes kids more active for awhile after lunch.
Schools are calmer all day.
I think lunch time is cool because you get to take time out from your school work and refuel your body with the nutritious food that your cooks prepare for you.