Scientists in California found that the cold could help us lose weight. Being in the cold increases levels of a protein that makes brown fat. This burns energy and helps us lose weight. White fat stores energy and so we put on weight. The researchers said air conditioning and heating keep us warm. This means we do need so much brown fat. Workers who work in cold temperatures outside have a lot more brown fat than people who work indoors.

The research was on two groups of mice. One group was given the brown-fat protein. This group gained 30 per cent less weight after having a high-fat diet. This research could help obese people, who have lower levels of brown fat than thinner people. The head researcher said the protein could greatly help the treatment and prevention of obesity. Higher levels of the protein could lead to weight loss, even if people eat the same amount of food.