Slow-growing infants will catch up with their peers over time with the right care from their parents, according to a new study.

Researchers from the University of Bristol, U.K., have found that children who put on weight slowly in the initial months of their lives have managed to catch up to their peers by the age of 13, but remained shorter and lighter than many of their peers.

The research team looked at data from 11,499 participants, who took part in a large study in the 1990s. They found that 507 children who were gaining weight slowly before the age of eight weeks (early group) recovered quickly and had almost caught up by the age of 2. Another group of 480 children who gained weight slowly until the age of 7 (later group) also caught up with their peers between 7 and 10 years.

However, children belonging to this later group were found to remain shorter and lighter than their peers and those in the early group at the age of 13. Children in the early group were on average 5.5 lbs (2.5kg) lighter and 1.28 inches (3.25cm) shorter than their peers, while children in the later group were on average 12.1 lbs (5.5kg) lighter and almost 1.57 inches (4cm) shorter than their peers.

The differences in the recovery patterns between the groups were likely due to the different reasons for slow weight gain, according to a report by BBC. But there was little difference in recovery patterns between boys and girls.

"The reason the early group caught up more quickly may be because those infants had obvious feeding difficulties and were more readily identified at the eight-week check, resulting in early treatment leading to a more rapid recovery. However, as Children of the 90s is an observational study, there is limited information available about which infants received nutritional supplements or medical treatments," professor Alan Emond, from University of Bristol, said in a statement.

"Those children who showed slow weight gain later in infancy took longer to recover, because of the longer period of slow growth and because their parents were smaller and lighter too."

The new findings bring relief to parents, with researchers assuring them that slow-growing children eventually do catch up to within the normal range.

Researchers also insist that health professionals should not increase calorie intake of the children unless they need intervention due to ill health, as it might put the children at a risk of obesity later in life.

The findings of the study are published in the journal Pediatrics.