The breakthrough holds out the hope that in future some people could take an “exercise tablet” every day to help keep them fit and healthy.

Researchers in Aberdeen and Beijing found the gene mutation that may explain why some people shun exercise and are more likely to put on weight and develop health problems.

Lead researcher Professor Wei Li, of the Institute of Genetics and Developmental Biology in Beijing, said: “We discovered that mice with this gene mutation were typical couch potatoes. They walked only about a third as much as a normal mouse, and when they did move they walked more slowly.

“The mice became fat and they also developed other symptoms similar to a condition in people called metabolic syndrome – a medical term for those with a combination of risk factors related to diabetes, high blood pressure and obesity.