Sitting makes your bum bigger

If you happen to sit more often you are more likely to have a bigger bottom. Experts say that the pressure put on areas of the body used for sitting produces up to 50 percent more fat in those parts.

This can explain why couch potatoes and other sedentary behaviour makes you fat especially when combined with a lack of exercise. Even people with healthy diet and exercise habits will be affected if they spend long periods sitting behind a desk,according to researchers. Researchers found that preadipocyte cells - the precursors to fat cells - turn into fat cells and produce even more fat when subject to prolonged periods of 'mechanical stretching loads' - the kind of weight we put on our body tissues when we sit or lie down.

Professor Amit Gefen, from Tel Aviv University, said: "Obesity is more than just an imbalance of calories. Cells themselves are also responsive to their mechanical environment. Fat cells produce more triglycerides [the major form of fat stored in the body], and at a faster rate, when exposed to static stretching.
"There are various ways that cells can sense mechanical loading. It appears that long periods of static mechanical loading and stretching, due to the weight of the body when sitting or lying, has an impact on increasing lipid [fat] production."
These findings indicate that we need to take our cells' mechanical environment into account as well as pay attention to calories consumed and burned, said Professor Gefen.
He warned that, while there are extreme cases of people confined to wheelchairs or beds due to medical conditions, many people live a too sedentary lifestyle - spending most of the day behind a desk.

Studying MRI images of the muscle tissue of patients paralysed by spinal cord injuries, researchers noticed that, over time, lines of fat cells were invading major muscles in the body.

This spurred an investigation into how mechanical load - the amount of force placed on a particular area occupied by cells - could be encouraging fat tissue to expand, according to the newspaper.

The research has been published in the American Journal of Physiology - Cell Physiology.