White fat cells can be turned into energy-burning brown fat using CRISPR gene-editing technology. These engineered cells have helped mice avoid weight gain and diabetes when on a high-fat diet, and could eventually be used to treat obesity-related disorders, say the researchers behind the work.

Human adults have plenty of white fat, the cells filled with lipid that make up fatty deposits. But we have much smaller reserves of brown fat cells, which burn energy as well as storing it. People typically lose brown fat as they age or put on weight. While brown fat seems to be stimulated when we are exposed to cold temperatures, there are no established methods of building up brown fat in the body.