精选外刊｜《自然》：体重反弹别怪自制力，怪你的脂肪细胞

** Fat cells have a 'memory' of obesity ** Even after drastic weight loss, the body's fat cells carry the 'memory' of obesity, research shows — a finding that might help to explain why it can be hard to stay trim after a weight-loss programme.

The results suggest that people trying to slim down will often require long-term care to avoid weight regain, says study co-author Laura Hinte, a biologist at ETH Zurich in Switzerland.

“It means that you need more help, potentially, “ she says.

“It’s not your fault.”

To understand why weight can pile back on so quickly, Hinte and her colleagues analysed fat tissue from a group of people with severe obesity, as well as from a control group of people who had never had obesity.

They found that some genes were more active in the obesity group’s fat cells than in the control group’s fat cells.

Even weight-loss surgery did not budge that pattern.

Two years after the participants with obesity had had weight-reduction operations, their fat cells’ genetic activity still displayed the obesity-linked pattern.

To better understand the effects of this memory, the researchers studied fat cells from mice that had slimmed down after being obese.

These cells absorbed more sugar and fat than did fat cells from control mice that had never been obese.

The formerly obese mice also gained weight faster on a high-fat diet than control mice did.

Preventing obesity to begin with is key, study co-author Ferdinand von Meyenn adds.

People who lose weight “can [stay] lean, but it will require a lot of effort and energy to do that”, he says, adding that his team’s findings could help to remove some of the stigma surrounding obesity.