Being cold helps you lose weight

Being cold helps you lose weight, a new study found.

Exercise or being exposed to low temperatures creates more ‘good’ brown and beige types of body fat which burns calories in the body.

Previous research has found being cold mimics the effects of exercise, protecting against obesity and improving metabolic health.

Now, a new study has discovered how exposure to cold dramatically alters the composition of bacteria the gut, and this leads to fat-burning, improved glucose metabolism, and reduced body weight.

The findings could provide new treatments for overweight or obese people, researchers said.

Professor Mirko Trajkovski of the University of Geneva said: ‘We provide compelling evidence that gut microbes play a key role in our ability to adapt to the environment by directly regulating our energy balance.

‘We are excited about exploring the therapeutic potential of these findings and testing whether targeting some of these microbes could be a promising approach for preventing obesity and related metabolic conditions.

While ordinary white fat- known as ‘bad’ fat – piles on when we eat more calories than we burn, brown fat seems to burn excess calories to generate heat.

We know babies have lots of brown fat — they need it to keep warm — but studies have shown there are small amounts in the necks of adults, too.

Experts believe that certain activities could switch on this fat, potentially helping to burn calories at a greater rate.

And studies have shown certain activities, such as sleeping in a cold, can trigger the formation of more brown fat in the body.

Gut microbes have also been implicated in obesity and obesity-related conditions like Type 2 diabetes and heart disease.

It is thought the composition of millions of bacteria in our intestines can affect how we metabolise different foods and, therefore, how much weight we gain.

Researchers theorised the health benefits of being exposed to cold may be linked to gut bacteria.

As part of the new study, they exposed mice to cold temperature of 6°C (43°F) for up to 10 days.

They discovered this caused a major shift in the composition of the mice’s gut microbes and preventing them from gaining weight.

Then, the cold-induced gut bacteria were transplanted into other mice that did not harbour gut microbes because they had been raised in a germ-free environment.

It was found these mice had improved glucose metabolism, increased tolerance to cold temperatures.

The mice also lost weight as the changes in gut bacteria promoted the formation of beige fat.

Professor Trajkovski said: ‘These findings demonstrate that gut microbes directly regulate the energy balance in response to changes in the environment.

However, after three weeks of cold exposure, body weight began to stabilise.

The intestine grew so it absorbed more nutrients from food, offsetting any additional weight loss.

He added: ‘These findings demonstrate that gut microbes enable mammals to harvest more energy from food as a way to adapt to the increased energy demand associated with long periods of cold exposure, thereby helping to protect against hypothermia.

‘We were surprised to see that gut microbes had such dramatic effects on the structure and function of the intestine.

The team now plans to study the molecular mechanisms by which gut microbes sense changes in the environment, such as cold, which affect how much energy a person uses up.

They are also looking into how changing certain gut bacteria may prevent obesity by remodelling intestinal tissue and thereby decreasing the absorption of nutrients in the gut.