my baby is 8 months old.her birth weight is 3.6 now her weight 7 .how to increase her weight and I don't know why she is not gaining weight.but she very active..

A. Hello mom her metabolism could be such that she might not able to gain that very easily, babies are normally expected to almost double their birth weight by the age of 4 to 6 months and then triple by the age of 1 year, currently as per their age they can be given semi solids and mashed consistency foods and alternate it with your feed.