An adult's propensity to pack on the pounds is directly linked to early childhood diet, a new study out of the University of Calgary suggests.

The study by Raylene Reimer of the faculty of kinesiology is published in the current issue of Journal of Physiology.

"I believe this study clearly shows that the composition of early childhood diet may have a direct lifelong impact on genes that control metabolism and obesity risk," Reimer said in a statement.

"This study clearly indicates that diet composition alone can change the trajectory of circulating satiety hormones and metabolic pathways that influence how we gain weight or control blood sugar as adults."

Reimer looked at three groups of rats who at a very young age were given three different diets: a high-protein diet, a high-fibre diet and a control diet.

When the rats became adults they were switched to a high-fat, high-sugar diet, which Reimer said reflects the typical diet in North America.

"We selected high fibre because we know that Canadians eat only about half of the fibre that they should. We also knew lots about the detriment of a low-protein diet but not as much about the implications of a high-protein diet, which may be more topical given the popularity of the Atkins and South Beach type diets."

The rats raised on the high-protein diet put on much more weight than those on the high-fibre diet, who put on the least weight of the three groups.

"There are many similarities between the rat models we use and humans in terms of how obesity and diabetes develop," Reimer said.

Reimer said people can battle susceptibility to chronic diseases through exercise and a strict diet, but that job could be harder if childhood diet determines propensity to pack on the pounds.

"It is interesting to note, however, that there are small pockets of evidence emerging that some very specific treatments at very defined times during development can reverse some of the negative effects. This will be one of the most exciting new areas of inquiry in this field."