MOTHERS of small babies should not panic into over-feeding their children, experts warned today, as a study revealed faster weight gain in infancy could make them fat in later life.
Infants who were fed milk enriched with nutrients had higher body fat mass than those who were given standard formula, according to the study.
Previous studies have shown a link between over-nutrition in childhood and overweight adults in animals, but the researchers said this is the first demonstration in humans when other factors such as the size of mothers is ruled out.
Body fat mass in five to eight-year-olds was 22pc to 38pc greater in those who were given nutrient-enriched milk than babies than those who had standard formula, according to a team based at the University College London Institute of Child Health.
The scientists said the findings, published online in the American Journal of Clinical Nutrition, have important public health implications and pointed out they confirm previous estimates that more than 20pc of adult obesity may be caused by over-nutrition or other early excessive weight gain in infancy.
Professor Atul Singhal, who led the study, said mothers should breastfeed if possible.
"It's easier to regulate appetite and harder to overfeed breastfed babies," he said.
"If they can't breastfeed they shouldn't overfeed because babies should not put on too much weight too quickly.
"Small babies will put on weight faster than other babies anyway as they try to catch up.
"Mothers should not add fuel to the fire by giving them any more to try to make them heavier than their percentile."
"It's not a competition," Prof Singhal insisted.
"Parents need to relax more about the weight."
Researchers looked at two randomised, controlled, double blind studies -- where neither they nor the mothers knew which kind of milk they were assigned -- involving small newborn babies.
The study concluded: "This study robustly demonstrates a link between early nutrition and having more fat in later life in humans."