Scientists at the University of California discovered that staying in the cold could help us lose weight. Exposure to the cold increases levels of a protein that helps make brown fat, which burns energy and keeps us warm. It also helps us lose weight. White fat stores excess energy and so we gain weight. The researchers said that because of air conditioning and heating, we stay warm. This means our body does not need so much brown fat. They said that workers who work outside in cold temperatures, "have a significant amount of brown fat when compared to same-aged indoor workers".

The research was on two different groups of mice. One group was injected with the brown-fat protein. This group gained 30 per cent less weight after both groups had high-fat diets. The researchers say this could help in the fight against obesity. Obese people have lower levels of brown fat than thinner people. Head researcher Hei Sook Sul said: "This protein could become an important target for research into the treatment and prevention of obesity." She said that increasing the levels of this protein could lead to weight loss even if people eat the same amount of food.