Over-eating at an early age may stay well into adulthood

Jan 24 2005

Melbourne researchers have found that over-eating at a very young age can have a long-lasting effect on the body and in particular seems to enhance the production of hormones made in fat and involved in metabolism.

The study, prompted by the large increase in childhood obesity, found that many of the initial effects of over-feeding at an early age remained with rats well into adulthood, regardless of the diet they ate as an adult.

Dr Margaret Morris from the University of Melbourne’s Department of Pharmacology says, “We found that over-nourishment from a very young age had long-lasting effects on hormones made in fat, and the fact that these occurred regardless of the adult diet suggests that early nutrition can have a prolonged impact on the body, which may affect long-term control of body weight.”

Soon to be published in the American Journal of Physiology, the most striking finding of the study was that baby rats allowed to feast on their mother’s milk during the early days of life had elevated levels of an enzyme involved in metabolism that remained with them into adulthood.

The enzyme, called 11 Beta-HSD, is produced in fat and plays a role in converting inactive cortisone to active cortisol – a steroid hormone that affects metabolism and helps to maintain blood pressure and the body’s anti-inflammatory response.

“These findings suggest that metabolic programming may be laid down early in life and that over-eating in early life could enhance the body’s capacity to create these metabolic hormones.”

The effects of over-nutrition at an early age also had a big impact on body weight. These rats remained heavier than other rats for a very long time, despite being fed identical diets post-weaning.

Whether the rats were fed a high fat or a normal diet as an adult, the ones that had been allowed to over-eat as babies always remained heavier than other rats on the same diet.

Dr Morris will present more of the group’s research into the effects of early nutrition at the Australian Neuroscience Society’s annual meeting in Perth at the end of this month. PhD student, Elena Velkoska, who is investigating the long-term effects of under-eating during the early days of life will also present at the conference.

Ms Velkoska is supported by a National Heart Foundation of Australia postgraduate scholarship. The project also received support from the National Health and Medical Research Council.