My son is 2years and 10 months his weight is 13 kilos and he doesn't eat much. what can i do to make him healthy?

Encourage him!: At your son's age, 13 kilos falls around the 25th percentile. So he is still a decent weight for his age. If he isnt eating much however, i would encourage him to try new and different foods. I would try to offer him solid foods before a drink. Children his age often fill up on liquids and thus arent hungry. You could also offer him a childrens multivitamin each day.