Trying to lose weight? Just stand outside in the cold!

IF the thought of a January diet leaves you cold, here’s some good news.

The key to weight loss could simply be lowering your body temperature – and just braving the winter chill without a coat could help fat melt away, it is claimed.

The theory hinges on the properties of two types of body fat. The troublesome white variety soaks up extra calories and stores them in bellies, love handles and thighs.

But adults also have a small amount of brown ‘healthy fat’. This specialises in burning off calories and generates heat as it does so.

Babies have lots of brown fat to keep them warm and adults who have more brown fat are slimmer than those without.

Researchers from the University of California, Berkeley, showed a protein called Zfp516 is key in turning white fat into something that resembles brown. With around 90 per cent of the fat in an adult’s body of the unhealthy variety, finding a

‘Converted into healthy fat’

way of browning it could have a big impact. Importantly, cold temperatures ramp up production of Zfp516.

And the more there is, the more white fat is converted into calorie-burning brown fat. In one experiment, mice that were genetically engineered to make large amounts of Zfp516 put on 30 per cent less weight than those that hadn’t been – despite feasting on fatty food.

The researchers said: ‘It has been noted that outdoor workers in northern Finland who are exposed to cold temperatures have a significant amount of brown fat when compared with same-aged indoor workers but overall the percentage of brown fats in adults is small compared to white fat.’

Mice with high levels of the browning protein also found it easier to process sugar – something that should cut their odds of diabetes, the journal Cell Metabolism reports.

In future, it may be possible increase levels of the browning protein – and so brown fat – without the need to endure the cold.

Researcher Jon Dempersmier said: ‘If we can harness this, we can try to use this in therapy for weight loss and diabetes.’