my baby is now 4 months old but he is not getting healthy will u tell me why

A. See first you have to understand the calculation that we do for the weight gain it is supposed to be 500 g minimum in a month so if your child has gained 2 kg more than the birth by the time of four months complete it’s healthy otherwise your food is not enough in that case I would advise you to start giving combination feeding of formula along with breast