Couch potatoes may have their genes to blame, a recent study found.
Scientists involved in the study have discovered a genetic mutation that makes some people lazier than others - a discovery that could pave the way to a cure.
The newly-dubbed "couch potato gene" plays a crucial role in the brain, making some people less likely to exercise. As a result, these people are more likely to gain weight and develop health problems.
In their study, researchers from the University of Aberdeen and the Chinese Academy of Sciences compared normal mice with those that had the key mutation. In doing so, they found that the gene produces a protein that plays a vital role in the brain's dopamine system, which increases someone's inclination to carry out physical activity.
Mice with the mutated gene were found to have fewer of this type of dopamine receptor on the surfaces of their brain cells. Instead, their receptors were stuck within the cell.
Wei Li, lead author of the study from the Institute of Genetics and Developmental Biology in Beijing, confirmed that their results could lead to a possible treatment for humans.
"We discovered that mice with this gene mutation were typical couch potatoes," he said. "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."
Results of their study were published in the journal PLOS Genetics.
