减肥为何易反弹？研究：脂肪细胞“记得”你胖过！

对于任何尝试过减肥的人来说，成功减重之后维持好自己的体重不反弹，无疑是一件更需要毅力的事情。改变饮食与生活习惯的持久战太过艰难，身体似乎对“胖”有着深刻的体态记忆，难以轻易抹去。

今年11月，《自然》杂志发表的一项研究显示，即使大幅减重后，身体的脂肪细胞仍携带了对肥胖的“记忆”——该发现或解释了为何成功减重后很难维持。

A study published in the journal "Nature" on Nov 18 showed that "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 keep the weight off after a weight-loss programme."

脂肪细胞有“肥胖记忆”——这暗示了为什么减肥后保持体重很难。

这种记忆的出现，是因为经历过肥胖会改变我们的“表观基因组”（epigenome），可帮助上调或下调基因活性。对于脂肪细胞来说，基因活性的变化似乎会让它们无法正常运转。

研究指出，这种基因活性的变化，在身体回到健康体重后仍会长期存在。

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 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. epigenome /ˌepɪˈdʒiːnoʊm/ 表现基因组

研究结果表明，想要瘦身的人需要长期维持才能避免体重反弹。

该研究共同作者、苏黎士联邦理工学院的生物学家劳拉·欣特（Laura Hinte）说，“长期维持体重意味着你可能需要更多帮助，复胖并不是你自己的问题。”

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 the Swiss Federal Institute of Technology (ETH) Zurich. "It means that you need more help, potentially," she says. "It's not your fault."

为了理解减重后为何会快速反弹，欣特和她的同事分析了一组重症肥胖人群的脂肪细胞和从未肥胖过的对照组的脂肪细胞。他们发现，肥胖组的脂肪细胞的部分基因比对照组的更活跃。

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.

即使减肥手术也无法改变这种情况。肥胖受试者在接受减肥手术的两年后，虽然体重降了很多，但他们脂肪细胞的基因活性仍然处在肥胖模式。

Even weight-loss surgery did not budge that pattern. Two years after the participants with obesity had undergone weight-reduc-tion operations, they had lost large amounts of weight — but their fat cells' genetic activity still displayed the obesity-linked pattern.

科学家在减重较大的小鼠中也发现了类似结果。研究团队通过让肥胖小鼠节食，测试了这些变化的持续时间。小鼠成功瘦身的几个月后，它们表观遗传组的变化依然存在，就好像这些细胞还有在肥胖身体内的“记忆”。

The scientists found similar results in mice that had lost large amounts of weight. 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. durability /ˌdʊrəˈbɪləti/持久性，耐用性

肥胖诱发的DEG变化在减重后仍持续存在

该研究的共同作者、苏黎士联邦理工学院的表观遗传组专家费迪南德·冯·梅恩（Ferdinand von Meyenn）说，身体对肥胖的记忆有多久，这个问题还不清楚，“这个记忆可能会有一个丧失的时间窗，但我们还不知道。”

It's not clear how long the body remembers obesity for, says study co-author Ferdinand von Meyenn, an epigenome specialist at ETH Zurich. "There may be a time window when this memory will be lost," he says. "But we don't know."

目前很难确定这些变化中的哪一些导致了脂肪细胞的记忆长期存在，科学家们还在进一步研究中。

It is currently challenging to pinpoint which of these changes are causing the long-term retention of fat cell memory, and scientists are continuing their research to delve deeper into this.

这些研究研究结果提示我们，对于肥胖而言，预防才是关键，一旦肥胖了，你的身体就记住了肥胖的状态，再想消除就绝非易事。不过大家也不要因此失去减肥的信心。减肥成功之后继续用科学合理的方式保持健康饮食和运动，是不会让体重出现大幅度反弹的。

编辑：黎霈融

来源：自然系列 Nature

参考文献：

Hinte, L. C. et al. Nature https://doi.org/10.1038/s41586-024-08165-7 (2024).