唐朝是汉族王朝吗:饥饿荷尔蒙导致体重反弹

NEW YORK – Any dieter knows that it's hard to keep off weight you've lost. Now a study finds that even a year after dieters shed a good chunk of weight quickly, their hormones were still insisting, "Eat! Eat! Eat!"

纽约——每位节食者都清楚要保持成功减去的体重是多么困难。现在科学研究表明，即便节食者一年里快速减去大量体重，但他们的饥饿荷尔蒙仍然告诉自己，“吃，吃，吃！”

The findings suggest that dieters who have regained weight are not just slipping back into old habits, but are struggling against a persistent biological urge.

研究建议每位节食者，体重反弹并不是因为倒退至先前的旧习惯，而是身体不断的与持续的饥饿荷尔蒙做抵抗。

"People who regain weight should not be harsh on themselves, as eating is our most basic instinct," Joseph Proietto of the University of Melbourne in Australia, an author of the study, said in an email. The research appears in Thursday's issue of the

New England Journal of Medicine

澳大亚墨尔本大学的Joseph Proietto研究作者周四在新英格兰医学期刊发表的研究中提到：“吃是我们最基本的本能，在减肥时出现体重反弹不能对此太苛刻。”

Weight regain is a common problem for dieters. To study what drives it, Proietto and his colleagues enrolled 50 overweight or obese patients in a 10-week diet program in Australia. They wanted to see what would happen in people who lost at least 10 percent of their body weight. Ultimately, only 34 people lost that much and stuck with the study long enough for analysis.

体重反弹对每位减肥者来说是个普遍问题。为了研究到底是什么原因驱使这种现象发生，Proietto与他的同事在澳大利亚用10周时间，招募了50位超重或肥胖病人进行一项节食计划研究。他们需要了解这些超重或肥胖病人在减去自重的10%后会发生什么。最终，仅有34位达到了预期目标，并留有足够时间进行原因分析与研究。

The program was intense. On average, the participants lost almost 30 pounds during the 10 weeks, faster than the standard advice of losing 1 or 2 pounds a week. They took in 500 to 550 calories a day, using a meal replacement called Optifast plus vegetables for eight weeks. Then for two weeks they were gradually reintroduced to ordinary foods.

此项研究强度很大。在10周时间内，每位参与者平均减掉了几乎30磅左右体重，远远快于每周1-2磅的常规建议。每位参与者每天要消耗500-550卡路里，8周时间里他们每天只吃一种叫Optifast（超低卡路里）外加新鲜蔬菜搭配的食物。剩余2周，渐渐回到正常食物饮食。

Despite counseling and written advice about how to maintain their new weights, they gained an average of 12 pounds back over the next year. So they were still at lower weights than when they started.

尽管有如何保持研究者各自重获得的新体重方面的咨询与书面建议，但在过去一年里平均每人仍增重12磅左右。不过与他们开始研究时相较还是保持在较轻的重量。

The scientists checked the blood levels of nine hormones that influence appetite. The key finding came from comparing the hormone levels from before the weight-loss program to one year after it was over. Six hormones were still out of whack in a direction that would boost hunger.

科学家分析了影响饮食的血液中9种荷尔蒙水平。对比减肥前荷尔蒙水平变化的研究表明，较之前有所升高。其中6种荷尔蒙水平的紊乱表现，在某方面促成饥饿感是激增的主要原因。

The dieters also rated themselves as feeling hungrier after meals at the one-year mark, compared to what they reported before the diet program began. Experts not connected to the study said the persistent effect on hormone levels was not surprising, and that it probably had nothing to do with the speed of the weight loss.

每位减肥参与者在完成一年研究后，对比研究开始前各自的报告时发现，他们在每次饭后会感觉更加饥饿。专家表示，发生这种情况与研究中持续施加对荷尔蒙激素的影响没有关系并不意外，且与快速减肥亦无太多关联。

People who lose less than 10 percent of body weight would probably show the same thing, though to a lesser degree, said Dr. George Bray of the Pennington Biomedical Research Center in Baton Rouge, La. A key message of the study is that "it's better not to gain weight than to try to lose it," Bray sai

佩宁顿巴顿鲁治生物研究所的George Bray博士说：“通常他们减去低于10%的体重很可能会出现同样的结果，尽管程度稍轻”Bray还说，实验室中研究表明：“不增肥比减肥更有用。”

Why would a dieter's body rebel against weight loss? It's an evolutionary holdover from earlier times, when weight loss could threaten survival and reproduction, says Dr. Rudolph Leibel, an obesity expert at Columbia University in New York. So "it's not surprising at all" that our bodies would fight back for at least a year, he said. "This is probably a more or less permanent response."

为什么减肥者在研究中会出现身体反抗减肥的情况呢？纽约哥伦比亚大学的肥胖问题专家Rudolph Leibel博士认为：“减肥时会威胁或再造荷尔蒙，与早前相比就是进化延期。因此这根本就没什么，我们的身体便会至少在一年中抵抗减肥，而且很可能衍变成永久反应。”

People who lose significant weight not only gain bigger appetite but also burn fewer calories than normal, creating "a perfect storm for weight regain," Leibel said. 

He said avoiding weight regain appears to be a fundamentally different problem from losing weight in the first place, and that researchers should pay more attention to it. 

The study was supported by the Australian government, medical professional groups and a private foundation. Proietto served on a medical advisory board of Nestle, maker of Optifast, until last year.

Leibel博士还提到：“人们减掉难以置信的重量，不是为了获得更大的食量，而是燃烧掉比正常值更多的卡路里，创立完善的体重反弹体系。”

他还说：“研究者应当注意，应该将如何永久的制约体重反弹问题放在首要地位，而不是仅仅减重。”
此项研究由澳大利亚政府支持，医疗专业机构以及一家私有基金。截止去年，Proietto一直服务于Nestle医疗咨询委员会，亦是Optifast（超低卡路里的制造商）。