The eating habits of children can seem very strange at times to parents. During certain times they can seem to eat nothing and never be hungry and other times they may seem to be hungry all the time. Your child's pediatrician
is the best doctor
for you to discuss these issues. There are two very important principles to follow when determining if a child has a healthy diet. First, the child must be eating good foods. This means that they should be eating 4-5 servings of fruits and vegetables and limit the amount of sweets, fast food, fatty foods, and processed flour. Second, your child must be a healthy weight (which you have said he is). If you are feeding your child a good diet, and he is not overweight, then I would not worry
too much about his eating. I should note that there are childhood conditions where overeating is a problem. Children with diabetes seem hungry all the time and thus, it would not be a bad idea to get him screened at you next pediatric visit. If your son develops excessive thirst, excessive urination, or in any way gets lethargic, take him to his doctor right away. Another more rare condition is Prader-Willi syndrome. This is a genetic problem in which children cannot stop eating and become very obese. I would be shocked if this was your son's problem and it had not yet been diagnosed. Good luck.