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原文标题:Fat Cells Have a Memory of Obesity, Making It Hard to Lose Weight
链接:https://web.shanbay.com/reading/web-news/articles/qxwtq 难度:六级/考研 ![]() ![]() |
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Even after drastic weight loss, the body's fat cells carry the 'memory' of obesity — a finding that might help to explain why it can be hard to stay trim after a weight-loss programme. This memory arises because the experience of obesity leads to changes in the epigenome — a set of chemical tags that can be added to or removed from cells' DNA and proteins that help to dial gene activity up or down. For fat cells, the shift in gene activity seems to render them incapable of their normal function.This impairment, as well as the changes in gene activity, can linger long after weight has dropped to healthy levels, a study published in Nature reports. 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."It means that you need more help, potentially," she says."It's not your fault." ![]() ![]() |
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A lingering memory To understand why weight can pile back on so quickly after it is lost, 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, whereas other genes were less active.They also found similar results in mice that had lost large amounts of weight. In the fat cells of both humans and mice, the genes dialled up during obesity are involved in spurring inflammation and fibrosis — the formation of stiff, scar-like tissue.The genes that are turned down help fat cells to function normally. Research on mice traced these shifts in gene activity to changes in the epigenome, which has a powerful effect on how active a gene is, including whether it is turned on at all. The scientists tested the durability of these changes by putting obese mice on a diet.A few months after the mice had become lean again, the changes in their epigenomes persisted, as if the cells 'remembered' being in a body with obesity. ![]() ![]() |
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Rapid regain It's not clear how long the body remembers obesity for, says study co-author Ferdinand von Meyenn."There may be a time window when this memory will be lost," he says."But we don't know." 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, von Meyenn notes.People who lose weight "can stay lean, but it will require a lot of effort and energy to do that", he says. ![]() ![]() |