Chinese scientists have made a key discovery which could explain why some people are "couch potatoes". Scientists from the Chinese Academy of Sciences, Institute of Genetics and Developmental Biology (IGDB) in Beijing, found that a mutation in a gene which has a critical role in the brain may explain why some people are less inclined to exercise and are more likely to put on weight and develop health problems. Their study - published in PLOS Genetics - also raises the prospect that in the future there could be a personalized pill that could reverse the problem.

Professor Wei Li of the IGDB, where all the work was carried out, led the study. He said that mice with this gene mutation were typical couch potatoes, walking 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 human condition called "metabolic syndrome" - a medical term for those with a combination of risk factors related to diabetes, high blood pressure and obesity.