A spurt in growth early in childhood could lead to obesity later in life, research suggests. Scientists have found a link between rapid growth as a baby and the long-term rise in a person's metabolism.

Neil Metcalfe of Glasgow University, who led the research, compared the resting metabolic rates of zebra finches fed on a regular protein diet as they grew with birds switched from a low- to a high-protein diet halfway through their growth period. Zebra finches in the latter group experienced a spurt in growth because their diet had improved. Medcalfe also found that the resting metabolic rate as adults was 20% higher than if they had grown more steadily.

The results were published in the Proceedings of the Royal Society B journal. Metcalfe said a higher resting metabolic rate could lead to a rise in overall appetite levels. "In wild animals that might not be a problem," he said. "But in a western culture if you have a high appetite plus access to lots of high-fat foods then you could end up being obese."

He said growth spurts that had these effects were due to changes in diet as a baby, rather than hormonal growth spurts children experience at puberty.

The work adds to a growing body of evidence that the risk of developing diseases, including obesity, depends on nutrition in childhood. Of particular concern is a pattern in early childhood, called catch-up growth by scientists.

Catch-up growth, which might happen if a baby is born small and then given a diet to make it bigger or stronger, is known to store up problems for later life including greater blood pressure and a higher risk of coronary heart disease and diabetes.

Metcalfe said the effects of catch-up growth could be due to the fact that a person's basic body parts are being fixed in their first years.