Is there an obesity virus?

"If New Year dawned to the vision of a continuing obesity epidemic in your bathroom mirror, you will no doubt have already resolved - once again – to regain svelteness by the well known "calories in, calories out" equation – eat less, move more. Regular exercise and a balanced diet are, of course, the cornerstones of achieving a healthy weight. Yet some obesity specialists are now convinced that the cause of the Western world's expanding waistlines is rather more complex – and that there are additional factors to blame for unwanted weight gain. Here are some of them...

Room temperature

Scientists have shown that mice living in cosily warm cages are fatter than those lodging in more extreme temperatures – hot or cold. And the same may go for humans. A recent study by the American National Center for Healthy Housing found that the rise in obesity in the USA correlates with the increase in central heating and air conditioning in homes and offices. It seems unlikely that this research will result in widespread abandonment of either of these moderating influences. But it does underline useful weight loss strategies, says Carole Caplin. 'When you're hot and sweating, you're eliminating fluid retention – as well as stored toxins - rather than burning calories,' she says. 'That's why a steam or sauna is both healthy and promotes weight loss. When you're uncomfortably cold, on the other hand, your body works harder, burning fat to get warm. Cycling, brisk walks or playing any sport in cold weather is a way to feel good and burn calories.'"