According to this article our DNA could affect our ability to burn off fat through exercise. Dubbed the “unfitness gene” it seems one in five of us will be unable to lose weight no matter how much we exercise. Researchers asked 600 people to take up cycling and then tracked their improvements in fitness. They did this by measuring the amount the amount of oxygen they took in. By looking into the volunteers DNA they found 30 genes that affected oxygen intake and noticed that one in five had a combination of genes which meant their oxygen intake did not change despite the recent exercise. 10 per cent of the volunteers did see a massive improvement in their aerobic fitness, however, this could explain why some people find it hard to lose weight. Or it could just be that extra piece of cake you couldn’t resist.