“Brown fat” in healthy men may help body use up blood sugar in cold weather and at rest

Brown Adipose Tissue Improves Whole-Body Glucose Homeostasis and Insulin Sensitivity in Humans was recently published in Diabetes and found that in humans, brown fat was mostly found in newborn babies, who are more prone to heat loss and are unable to shiver to help keep themselves warm.

Brown fat (or brown adipose tissue) makes up for this by burning calories to create heat. As people grow older, there is less need for brown fat and it is mostly replaced by white fat ("bad fat").

Brown fat was found to burn calories in a recent study

However, as the study involved tests on just 12 men, an NHS Behind The Headlines report suggested "larger studies will be needed to confirm its findings".

The study looked at whether men with detectable levels of brown fat differed from men who didn't in terms of how their bodies dealt with sugar, particularly in cold conditions.

The researchers wanted to see what happened when the men were exposed to cold over five to eight hours.

Eating fatty foods will result in more white fat if you consume more calories than you burn off, and being overweight or obese increases the risk of developing type 2 diabetes.

The NHS analysis of the study concluded: “This small experimental study has suggested that in healthy men, brown fat can increase the uptake of blood glucose by cells in response to cold, and increase the amount of energy being used up at rest.

"Because of the small size of this study and the fact it only included healthy men, it is not possible to say whether the results are representative of the general population."

"With such small numbers, there could have been other unmeasured differences between the groups (such as biological and lifestyle differences) that influenced the results, rather than just brown fat."

"Other groups of people or other tests, rather than just this single experiment, could have given different results."