Infant body weight is tripled by age of –

The average birth weight of neonates is about 3 Kg. During first few days after birth, the newborn loses extracellular fluid equivalent to about 10% of the body weight. Most full term infants regain their birth weight by the age of 10 days. Subsequently, they gain weight at a rate of approximately 25 to 30 gm per day for the first 3 months of life. Thereafter they gain about 400 gm of weight every month for the remaining part of first year.