减肥后体重反弹 那不是你的错

Danny Cahill stood, slightly dazed, in a blizzard of confetti as the audience screamed and his family ran on stage. He had won Season 8 of NBC’s reality television show “The Biggest Loser,” shedding more weight than anyone ever had on the program — an astonishing 239 pounds in seven months.

丹尼·卡希尔(Danny Cahill)站在漫天的五彩纸屑中，微微有点懵，观众们在尖叫，他的家人飞奔上台。他获得了NBC频道电视真人秀节目《超级减肥王》(The Biggest Loser)第8季的冠军，在七个月时间里惊人地减掉了239磅（约217斤），超过了节目的其他所有参与者。

When he got on the scale for all to see that evening, Dec. 8, 2009, he weighed just 191 pounds, down from 430. Dressed in a T-shirt and knee-length shorts, he was lean, athletic and as handsome as a model.

2009年12月8日的那个晚上，他上秤让所有人看到，他从430磅（约390斤）减到了191磅（约173斤）。当时，他穿着T恤和及膝短裤，看起来精瘦强壮，和模特一样帅。

“I’ve got my life back,” he declared. “I mean, I feel like a million bucks.”

“我重新找回了生活，”他宣称，“我感觉好极了。”

Cahill left the show’s stage in Hollywood and flew directly to New York to start a triumphal tour of the talk shows, chatting with Jay Leno, Regis Philbin and Joy Behar. As he heard from fans all over the world, his elation knew no bounds.

卡希尔离开好莱坞那个节目的舞台，直接飞到纽约，开始进行一系列胜利者的脱口秀，接受杰·雷诺(Jay Leno)、里吉斯·菲尔宾(Regis Philbin)和乔伊·贝哈尔(Joy Behar)的采访。他收到世界各地粉丝们的来信，得意无比。

But in the years since, more than 100 pounds have crept back onto his 5-foot-11 frame despite his best efforts. In fact, most of that season’s 16 contestants have regained much if not all the weight they lost so arduously. Some are even heavier now.

然而在那之后，虽然尽了最大努力，身高5英尺11英寸（约1.8米）的他还是慢慢长了逾100磅（约90斤）。实际上，那一季的16名参赛者辛苦减掉体重之后，多数人有反弹，哪怕不是完全长回了减掉的体重。有些人的体重甚至超过了上节目前。

Yet their experiences, while a bitter personal disappointment, have been a gift to science. A study of Season 8’s contestants has yielded surprising new discoveries about the physiology of obesity that help explain why so many people struggle unsuccessfully to keep off the weight they lose.

这些经历对他们个人来说虽然意味着苦涩的失望，但对科学来说，却是天赐良机。对第8季参赛者的研究得出了令人惊讶的新发现，让我们更了解肥胖的生理机能，并有助于解释为什么那么多人减肥之后无法保持。

Kevin Hall, a scientist at a federal research center who admits to a weakness for reality TV, had the idea to follow the “Biggest Loser” contestants for six years after that victorious night. The project was the first to measure what happened to people over as long as six years after they had lost large amounts of weight with intensive dieting and exercise.

凯文·霍尔(Kevin Hall)是一家联邦研究中心的科学家，他承认自己酷爱电视真人秀。在卡希尔获胜之后，他产生了一个想法：跟踪研究《超级减肥王》的参赛者六年。人们在通过高强度饮食控制和锻炼实现大幅减轻体重之后，接下来长达六年的时间里会怎么样，这是第一个针对该问题的跟踪研究。 

The results, the researchers said, were stunning. They showed just how hard the body fights back against weight loss.

研究者说，结果令人震惊。结果表明，身体对体重减轻的反抗非常强烈。

“It is frightening and amazing,” said Hall, an expert on metabolism at the National Institute of Diabetes and Digestive and Kidney Diseases, which is part of the National Institutes of Health. “I am just blown away.”

“这令人恐惧和惊讶，”霍尔说。他是国家卫生研究院(National Institutes of Health)下属的国家糖尿病、消化系统疾病和肾病研究所(National Institute of Diabetes and Digestive and Kidney Diseases)的新陈代谢专家。“这令我大为震惊。”

It has to do with resting metabolism, which determines how many calories a person burns when at rest. When the show began, the contestants, though hugely overweight, had normal metabolisms for their size, meaning they were burning a normal number of calories for people of their weight. When it ended, their metabolisms had slowed radically and their bodies were not burning enough calories to maintain their thinner sizes.

这与静止代谢有关，也就是一个人在静止状态下消耗的热量。节目开始时，参赛者虽然严重超重，但是新陈代谢水平对他们的身材来讲是正常的，也就是说，他们静止时燃烧的热量对于他们那个体重的人来说，属于正常值。节目结束时，他们的新陈代谢急剧减缓，他们的身体没有消耗足够多的热量来保持较瘦的体型。

Researchers knew that just about anyone who deliberately loses weight — even if they start at a normal weight or even underweight — will have a slower metabolism when the diet ends. So they were not surprised to see that “The Biggest Loser” contestants had slow metabolisms when the show ended.

研究者已经知道，任何故意减轻体重的人——即使他们本来是正常体重或者体重偏低——在节食结束时，新陈代谢都会变慢。所以，他们对《超级减肥王》的参赛者在节目结束时新陈代谢减缓并不感到意外。

What shocked the researchers was what happened next: As the years went by and the numbers on the scale climbed, the contestants’ metabolisms did not recover. They became even slower, and the pounds kept piling on. It was as if their bodies were intensifying their effort to pull the contestants back to their original weight. 

令研究者们感到吃惊的是之后发生的事：随着时间流逝，体重增加，参赛者的新陈代谢水平没有恢复，甚至变得更慢了，于是体重也继续增加。好像他们的身体在努力让他们恢复到原来的体重。

Cahill was one of the worst off. As he regained more than 100 pounds, his metabolism slowed so much that, just to maintain his current weight of 295 pounds, he now has to eat 800 calories a day less than a typical man his size. Anything more turns to fat. 

卡希尔是情况最糟的一个。他的体重增加了逾100磅，新陈代谢变得非常缓慢，以至于为了维持目前295磅的体重，他每天不得不比这个体重的普通人少摄入800卡路里。多吃一口都长肉。

The struggles the contestants went through help explain why it has been so hard to make headway against the nation’s obesity problem, which afflicts more than a third of American adults. Despite spending billions of dollars on weight-loss drugs and dieting programs, even the most motivated are working against their own biology. 

这些参赛者所经历的困难有助于解释为什么美国的肥胖问题很难取得进展。超过三分之一的美国成年人有肥胖问题。数十亿美元被花在减肥药和减肥项目上面，但是连最积极的减肥者也是在与自身的生物机制对抗。

Their experience shows that the body will fight back for years. And that, said Dr. Michael Schwartz, an obesity and diabetes researcher who is a professor of medicine at the University of Washington, is “new and important.”

他们的经验表明，身体会反抗很多年。肥胖和糖尿病研究者、华盛顿大学(University of Washington)医学教授迈克尔·施瓦茨博士(Michael Schwartz)说，这一点是“新发现，也很重要”。

“The key point is that you can be on TV, you can lose enormous amounts of weight, you can go on for six years, but you can’t get away from a basic biological reality,” said Schwartz, who was not involved in the study. “As long as you are below your initial weight, your body is going to try to get you back.”

“重点是，你能上电视，你能把体重减轻很多，你能坚持六年，但你无法摆脱基本的生物学事实，”施瓦茨说。他没有参与这项研究。“只要低于原来的体重，你的身体就会努力让你恢复。”

The study’s findings, to be published on Monday in the journal Obesity, are part of a scientific push to answer some of the most fundamental questions about obesity. Researchers are figuring out why being fat makes so many people develop diabetes and other medical conditions, and they are searching for new ways to block the poison in fat. They are starting to unravel the reasons bariatric surgery allows most people to lose significant amounts of weight when dieting so often fails. And they are looking afresh at medical care for obese people. 

这项研究的结果将于周一发表在《肥胖》杂志(Obesity)上。它是为回答一些最基本的肥胖问题而进行的科学研究的一部分。研究者们正在努力弄清为什么肥胖让这么多人患上糖尿病或出现其他健康问题，他们也在寻找阻断脂肪中有害物质的新方法。他们开始揭示，为什么肥胖手术能让大部分人体重减轻很多而节食却经常失败。他们还在重新审视对超重者的医疗护理。 

The hope is that this work will eventually lead to new therapies that treat obesity as a chronic disease and can help keep weight under control for life. 

他们希望，这项工作将最终让我们找到新的治疗方法，把肥胖作为一种慢性病加以治疗，并且终生控制体重。

Most people who have tried to lose weight know how hard it is to keep the weight off, but many blame themselves when the pounds come back. But what obesity research has consistently shown is that dieters are at the mercy of their own bodies, which muster hormones and an altered metabolic rate to pull them back to their old weights, whether that is hundreds of pounds more or that extra 10 or 15 that many people are trying to keep off.

大部分试过减肥的人都知道保持减轻后的体重有多难，但是很多人在体重又增加时会怪自己。但是，肥胖研究一再表明，节食者受制于自己的身体，它通过调节激素和代谢率，让他们恢复原来的体重，不管是几百磅，还是很多人想努力避免长回去的那10磅或15磅。 

There is always a weight a person’s body maintains without any effort. And while it is not known why that weight can change over the years — it may be an effect of aging — at any point, there is a weight that is easy to maintain, and that is the weight the body fights to defend. Finding a way to thwart these mechanisms is the goal scientists are striving for. First, though, they are trying to understand them in greater detail.

每个人都有一个不必费力就能维持的体重。虽然不知道这个数字为什么会随着时间发生变化——可能是年龄增长的结果——但是在任何一个时间点，总有一个容易保持的体重，那也就是身体努力保卫的体重。找到对抗这一机制的方法是科学家努力追求的目标。不过，他们首先要努力了解更多细节。

Dr. David Ludwig, the director of the New Balance Foundation Obesity Prevention Center at Boston Children’s Hospital, who was not involved in the research, said the findings showed the need for new approaches to weight control. He cautioned that the study was limited by its small size and the lack of a control group of obese people who did not lose weight. But, he added, the findings made sense.

波士顿儿童医院(Boston Children’s Hospital)新平衡基金会肥胖预防中心(New Balance Foundation Obesity Prevention Center)的主管大卫·路德维希博士(David Ludwig)说，这些发现表明，需要寻找控制体重的新方法。他没有参与这项研究。他提醒说，这项研究的局限性在于规模小，没有对照组，也就是没有一组未参加减肥的肥胖者。不过，他补充说，这些发现说得通。

“This is a subset of the most successful” dieters, he said. “If they don’t show a return to normal in metabolism, what hope is there for the rest of us?”

他说，“他们是最成功的”减肥者，“如果他们的新陈代谢水平没有恢复正常，我们剩下这些人还有什么希望呢”。

Still, he added, “that shouldn’t be interpreted to mean we are doomed to battle our biology or remain fat. It means we need to explore other approaches.”

不过，他补充说，“这不应该被理解为，我们注定要对抗自身的生物机制，或者就只能继续肥胖。而应该被理解为，我们需要探索其他方法。”

All this does not mean that modest weight loss is hopeless, experts say. Individuals respond differently to diet manipulations — low-carbohydrate or low-calorie diets, for example — and to exercise and weight-loss drugs, among other interventions. 

专家们说，所有这些并不意味着适度减肥毫无希望。每个人对饮食控制（比如低碳水化合物或低热量饮食）以及锻炼和减肥药物等各种干预的反应是不同的。

But Ludwig said that simply cutting calories was not the answer. “There are no doubt exceptional individuals who can ignore primal biological signals and maintain weight loss for the long term by restricting calories,” he said, but he added that “for most people, the combination of incessant hunger and slowing metabolism is a recipe for weight regain — explaining why so few individuals can maintain weight loss for more than a few months.”

不过，路德维希说，仅仅减少热量摄入不是问题的答案。他说，“毫无疑问，有些例外的人能够不理会基本的生物信号，通过控制热量摄入长期保持体重减轻”，但是，“对大部分人来说，无休止的饥饿感和不断放缓的代谢加在一起，会导致体重重新增加，这就能解释为什么很少有人能保持体重减轻超过几个月”。

Cahill knows that now. And with his report from Hall’s group showing just how much his metabolism had slowed, he stopped blaming himself for his weight gain. 

卡希尔现在知道了。霍尔团队关于他的报告表明，他的代谢减缓了很多，所以他不再因为体重增加而责怪自己了。

“That shame that was on my shoulders went off,” he said. 

“我背负的羞耻感消失了，”他说。