From your measurements, his weight is just above the 50th percentile for his age which indicates his weight
is within normal
range. At 5-7 months you can start to feed him baby food - strained meats, vegetables, fruits, infant cereals, if he is refusing the infant formula. Suggest following a meal schedule for the solids, such as 3 meals a day- breakfast, lunch, dinner and between you give him the bottle of formula, if he takes it.