A recent study has revealed that genetic obesity can be offset by physical activity.
The report, which was conducted by the Medical Research Council, revealed that the tendency towards being substantially overweight can be offset by around 40 per cent through regular exercise.
This could challenge the popular idea that obesity is largely unavoidable for some people.
A sample of over 20,000 men and women were studied for the project, with DNA samples and detailed outlines of physical activity compared.
Dr Christian Jessen, a Harley Street doctor and television presenter, said that people needed to take daily changes into consideration when planning their exercise routing.
"If it's really baking hot outside, obviously don't go for a run in the hot street – that's going to make you feel awful," he said.
"Why not go for a swim? It's an easier thing to do when the weather's hot. You have to choose your exercise according to the weather."