My baby is 7 week old. His weight is 3 kg 200 gm. how should I increase his weight.

A. What was your babies birth weight in the first 3 months, babies put on about 800-900grams each month. From 3-6 months, weight gain reduces to 1/2 kg/month. from 6-9 months, it becomes 1/3, and for 9-12 months, it becomes 1/4 kg. the birth weight doubles in the 4th month and triples when they reach 12 months of age.