您现在的位置: 纽约时报中英文网 >> 纽约时报中英文版 >> 健康 >> 正文

间歇性禁食成瘦身界新宠?

更新时间:2016-4-5 10:24:32 来源:纽约时报中文网 作者:佚名

Fasting Diets Are Gaining Acceptance
间歇性禁食成瘦身界新宠?

Mark Mattson, a neuroscientist at the National Institute on Aging in Maryland, has not had breakfast in 35 years. Most days he practices a form of fasting — skipping lunch, taking a midafternoon run, and then eating all of his daily calories (about 2,000) in a six-hour window starting in the afternoon.

马克·马特森(Mark Mattson)是美国国家老龄化研究所(National Institute on Aging,位于马里兰州)的一位神经科学家,35年来,他从未吃过早餐。大多数日子他都执行着一种特殊形式的禁食:不吃午饭,午后跑步,然后在从下午开始的6小时内摄入每日需要的所有热量(约2000大卡)。

“Once you get used to it, it’s not a big deal,” said Dr. Mattson, chief of the institute’s laboratory of neurosciences. “I’m not hungry at all in the morning, and this is other people’s experience as well. It’s just a matter of getting adapted to it.”

“一旦你习惯了,就很容易做到,”研究所神经科学实验室负责人马特森博士说。“我整个上午都完全不会感到饿,遵循这种禁食模式的其他人也有同感。你要应对的,就是个适应的问题。”

In a culture in which it’s customary to eat three large meals a day while snacking from morning to midnight, the idea of regularly skipping meals may sound extreme. But in recent years intermittent fasting has been gaining popular attention and scientific endorsement.

在习惯于一日三餐,从早到晚时不时还吃点零食的文化背景下,经常不吃早、午餐听起来可能有点极端。但近几年来,间歇性禁食日益获得了广泛的关注和科学界的认可。

It has been promoted in best-selling books and endorsed by celebrities like the actors Hugh Jackman and Benedict Cumberbatch. The late-night talk show host Jimmy Kimmel claims that for the past two years he has followed an intermittent fasting program known as the 5:2 diet, which entails normal eating for five days and fasting for two — a practice Mr. Kimmel credits for his significant weight loss.Fasting to improve health dates back thousands of years, with Hippocrates and Plato among its earliest proponents. Dr. Mattson argues that humans are well suited for it: For much of human history, sporadic access to food was likely the norm, especially for hunter-gatherers. As a result, we’ve evolved with livers and muscles that store quickly accessible carbohydrates in the form of glycogen, and our fat tissue holds long-lasting energy reserves that can sustain the body for weeks when food is not available.

畅销书里在宣传它,演员休·杰克曼(Hugh Jackman)和本尼迪克特·康伯巴奇(Benedict Cumberbatch)等名人也对它推崇备至。深夜脱口秀节目主持人吉米·坎摩尔(Jimmy Kimmel)称自己在过去的两年里一直奉行一种名叫“5:2轻断食”的间歇性禁食计划:正常进食五天,轻断食两天,坎摩尔先生认为自己能够显著减肥正是这种禁食法的功劳。禁食能改善健康的观念可以追溯到几千年前,希波克拉底(Hippocrates)和柏拉图(Plato)都是其最早的拥趸。马特森博士认为人类非常适合这种饮食方式:纵观人类历史,间歇性进食在大部分时间里都属常态,对于狩猎-采集者来说尤其如此。经过长期的演化,我们在肝脏和肌肉中储存糖原,以备迅速分解提供能量;而脂肪组织则是我们的长期能量储备,在缺乏食物时维持身体数周所需。

“From an evolutionary perspective, it’s pretty clear that our ancestors did not eat three meals a day plus snacks,” Dr. Mattson said.

马特森博士说:“从进化的角度来看,很明显我们的祖先是吃不到每日三餐外加零食的。”

Across the world, millions of people fast periodically for religious and spiritual reasons. But some are now looking at the practice as a source of health and longevity.

在世界各地,数以百万计的人因为宗教和心灵方面的原因定期禁食。如今,有人提出这种做法还能让人健康长寿。

Valter Longo, the director of the Longevity Institute at the University of Southern California, initially studied fasting in mice that showed that two to five days of fasting each month reduced biomarkers for diabetes, cancer and heart disease. The research has since been expanded to people, and scientists saw a similar reduction in disease risk factors.

南加州大学长寿研究所(Longevity Institute at the University of Southern California)所长瓦尔特·隆哥(Valter Longo)在小鼠中进行的初步研究表明,每个月禁食2至5天可减少糖尿病、癌症和心脏病的生物标志物。其后,科学家们在人身上也进行了同样的研究,发现疾病的风险因素出现了类似的减少。

Dr. Longo said the health benefits of fasting might result from the fact that fasting lowers insulin and another hormone called insulinlike growth factor, or IGF-1, which is linked to cancer and diabetes. Lowering these hormones may slow cell growth and development, which in turn helps slow the aging process and reduces risk factors for disease.

隆哥博士推测,禁食之所以会带来健康效益,是因为禁食可以降低胰岛素以及与癌症和糖尿病有关的另一种激素:胰岛素样生长因子-1(IGF-1)。降低这些激素可以减缓细胞的生长和发育,从而有助于延缓衰老过程,减少疾病的风险因素。

“When you have low insulin and low IGF-1, the body goes into a state of maintenance, a state of standby,” Dr. Longo said. “There is not a lot of push for cells to grow, and in general the cells enter a protected mode.”

“当你的胰岛素和IGF-1都较低时,身体就会处于类似于‘待机’的维护状态,”隆哥博士说。“此时细胞没有太大的生长压力,通常就会进入‘保护模式’。”

Critics say that health benefits or not, various forms of intermittent fasting are too impractical for most people.

批评者指出,且不论其是否有益于健康,很多形式的间歇性禁食对大多数人来说根本就没有可行性。

The 5:2 diet, for example, advocates eating without restrictions for five days and then consuming just 500 calories — roughly the equivalent of a light meal — on each of the other two days of the week. Another regimen, called alternate-day fasting, involves eating no more than 500 calories every other day.

例如,“5:2轻断食”倡导人们一周连续五天不受限制地进食后,其余两天每天仅摄入500卡路里——大致相当于一顿很清淡的饭。另一个方案称为“隔日禁食法”,亦即每隔一天热量摄入不得超过500卡路里。

A third regimen, which Dr. Mattson follows, is known as time-restricted feeding. The idea is to consume all of the day’s calories in a narrow window, typically six to eight hours, and fasting for the remaining 16 to 18 hours in a day. Studies of time-restricted feeding practices in both animals and humans have suggested that the practice may lower cancer risk and help people maintain their weight.

马特森博士采用的是第三种方案,称为“限时进食法”(time-restricted feeding)。主旨在于在较短的时间段(通常是6到8个小时)内摄入一天所需的全部热量,其余的16至18小时一直保持禁食状态。在动物和人体上进行的限时进食研究均表明,它可以降低患癌症的风险,还有助于人们保持体重。

The scientific community remains divided about the value of intermittent fasting. Critics say that the science is not yet strong enough to justify widespread recommendations for fasting as a way to lose weight or boost health, and that most of the evidence supporting it comes from animal research. Advocates say the body of research on intermittent fasting is growing rapidly and indicates that the health benefits are striking.

对于间歇性禁食的价值,科学界仍存在分歧。批评者认为,科学依据尚不足以将禁食作为减肥或促进健康的方法广泛推荐,且其中大部分支持性的证据都来自动物研究。而支持者们则称,有关间歇性禁食的研究正在迅速增多,它们都表明禁食可带来惊人的健康效益。

The 5:2 diet, in particular, is backed by “promising” studies that show that it lowers weight and improves blood sugar, inflammation and other aspects of metabolic health, said Joy Dubost, a registered dietitian and a spokeswoman for the Academy of Nutrition and Dietetics, the country’s largest organization of dietitians. She noted that fasting isn’t appropriate for pregnant women, people with diabetes and people on medications.

特别是“5:2轻断食”,一项“有前景”的研究显示,它可以降低体重、改善血糖、炎症以及其他方面的代谢健康,注册营养师乔伊·杜博斯特(Joy Dubost)说。她还是全美最大的营养师组织——美国营养与饮食学会(Academy of Nutrition and Dietetics)的女发言人。但她也指出,禁食不适合孕妇、糖尿病患者和正在接受药物治疗的人。

“Most people who do this understand that it’s not about binge eating,” Dr. Dubost said. “But they like that it gives them the freedom not to worry about calories, carbs and other restrictions on days when they’re not fasting.”

“禁食方案的执行者大多明白这不代表他们可以暴饮暴食,”杜博斯特博士说。“但他们很享受在无需禁食的日子里不必担心卡路里、碳水化合物和其他限制的那种自由感。”

Krista Varady, an associate professor of nutrition at the University of Illinois at Chicago, has studied the effects of alternate-day fasting on hundreds of obese adults. In trials lasting eight to 10 weeks, she has found that people lose on average about 13 pounds and experience marked reductions in LDL cholesterol, blood pressure, triglycerides and insulin, the fat-storage hormone.

位于芝加哥的伊利诺伊大学(University of Illinois)的营养学副教授克里什陶·瓦拉迪(Krista Varady)在数百名肥胖的成年人身上研究了隔日禁食的效果。在持续8到10周的试验中,她发现这些人的体重平均下降了约13磅(约合5.9千克),且其低密度脂蛋白胆固醇(LDL胆固醇)、血压、甘油三酯和胰岛素(刺激人储存脂肪的激素)都明显降低了。

Dr. Varady found in her research that intermittent fasting was easiest when people ate a moderately high-fat diet and were allowed to consume up to 500 calories on their fasting days. In her studies, 10 percent to 20 percent of people usually find the diet too difficult and quickly stop. Those who stick with it typically adjust after a rocky first few weeks.

瓦拉迪博士在她的研究中发现,当人们食用中高脂肪饮食,并容许他们在禁食日里摄入500卡路里的食物时,间歇性禁食最容易实现。在她的研究中,参与者里一般有10%到20%觉得这种饮食太难坚持,很快就放弃了。而其余的人虽然觉得开头十分难熬,但只要挺过了这头几周,很快就适应了过来。

“We’ve run close to 700 people through various trials,” Dr. Varady said. “We thought people would overeat on their feast days to compensate. But people for some reason, regardless of their body weight, can only eat about 10 or 15 percent more than usual. They don’t really overeat, and I think that’s why this works.”

“近700名受试者参与了我们的各种试验,”瓦拉迪博士说。“我们本以为他们会在非禁食日大吃特吃,以补偿自己在禁食日里的‘委屈’。但出于某些原因,无论参与者体重如何,他们都只比平常多吃了约10%或15%而已。他们其实并不会暴饮暴食,我想这就是禁食方案能够见效的原因。”

In 2011, Dr. Mattson and his colleagues reported a study of the 5:2 program that followed 107 overweight and obese women. Half of the subjects were assigned to eat no more than 500 calories each on two consecutive days each week. A control group was assigned to follow a low-calorie diet.

2011年,马特森博士和同事们报告了一项关于“5:2轻断食”的研究,该研究随访了107名超重和肥胖的妇女。其中一半的受试者被分配入禁食组,每周有连续的两天每天摄入的热量不得超过500卡路里。分配入对照组的受试者则遵循低热量饮食。

After six months, both groups had lost weight. But the intermittent fasting group lost slightly more — about 14 pounds on average — and had greater reductions in belly fat. They also retained more muscle and had greater improvements in blood sugar regulation.

6个月后,两组受试者的体重都减轻了。但间歇性禁食组减重略多——平均14磅(约合6.35千克)左右,腹部脂肪也有较大幅度的减少。他们的肌肉保有量也较大,血糖调节也取得了更大的改善。

Dr. Mattson’s interest in intermittent fasting grew out of work on animals that showed that alternate-day fasting protected mice from strokes, Alzheimer’s and Parkinson’s disease, and consistently extended their life spans by 30 percent. Dr. Mattson and his colleagues found that alternate-day fasting increased the production of proteins that protect brain cells, enhancing their ability to repair damaged DNA. Fasting, he said, acts as a mild stress that makes cells throughout the body stronger, shoring up their ability to adapt to later insults.

马特森博士对间歇禁食的兴趣源于一些动物研究,这些工作显示,隔日禁食可防止小鼠患上中风、阿尔茨海默氏症和帕金森氏症,并可将其寿命延长30%。马特森博士和同事们发现,隔日禁食可以让身体合成更多保护脑细胞的蛋白质,增强其修复受损DNA的能力。他还说,禁食可以给身体一个温和的应激压力,让全身的细胞都更强壮,加强它们对以后的损害的适应能力。

In this way, intermittent fasting is like exercise, which causes immediate stress and inflammation, but protects against chronic disease in the long run. Eating fruits and vegetables may have a similar effect. While very large doses of antioxidants can cause cancer in humans, moderate amounts of exposure can make cells more resilient, Dr. Mattson said.

于是,间歇性禁食就像是一种锻炼,虽然引起了暂时的应激和炎症,但从长远来看却可以预防慢性疾病。食用水果和蔬菜也可能产生类似的效果。马特森博士说,虽然大剂量的抗氧化剂对人有致癌作用,但适量摄入却可以增强细胞的韧性。

“There is overlap between the way cells respond to exercise, to fasting, and even to exposure to some of the chemicals in fruits and vegetables,” he added.

“细胞对运动、禁食、乃至水果和蔬菜中的某些化学物质的反应都有部分相通之处。”他补充道。

Dr. Mattson is now starting a rigorous clinical trial of people 55 to 70 years old who are prediabetic and at high risk for developing Alzheimer’s disease. He plans to study whether intermittent fasting may slow cognitive decline.

现在,马特森博士启动了一项严格的临床试验,纳入了年龄在55岁到70岁,处于糖尿病前期,且阿尔茨海默氏症发病风险较高的中老年人。他计划研究间歇性禁食是否会减缓认知能力的衰退。

Dr. David Ludwig, a professor of nutrition at the Harvard T. H. Chan School of Public Health, said one benefit of fasting is that it forces the body to shift from using glucose for fuel to using fat. During this process, the fat is converted to compounds known as ketones, a “clean” energy source that burns more efficiently than glucose, like high-octane gasoline, Dr. Ludwig said.

哈佛大学公共卫生学院(Harvard T. H. Chan School of Public Health)的营养学教授大卫·路德维希(David Ludwig)博士表示,禁食的好处之一在于它迫使身体从使用葡萄糖作为燃料改为使用脂肪。在此过程中,脂肪被转化为酮,一种更为“清洁”,燃烧效率高于葡萄糖的化合物,就像高辛烷值汽油那样,路德维希博士说。

The same process, known as ketosis, occurs when people go on extremely low-carb, high-fat diets. Dr. Ludwig said ketones seem to have unique effects on the brain. High-fat diets, for example, have been used for years to treat people who suffer from epileptic seizures.

当人长期采用极低碳水化合物、高脂肪饮食的时候,也会发生同样的过程,称为酮症。路德维希博士说,酮似乎对大脑有种特殊影响。例如,多年来,高脂肪的饮食一直被用于治疗癫痫发作患者。

“There are extensive reports of children who had debilitating seizures who were cured on ketogenic diets,” Dr. Ludwig said. “If it benefits the brain to prevent seizures, then maybe it benefits the brain in other ways.”

“大量报道称生酮饮食治愈了因癫痫发作而身体虚弱的患儿,”路德维希博士说。“如果它可以防止癫痫发作,那么或许它对脑部还有其他方面的好处。”

Dr. Ludwig noted that the long-term effectiveness of fasting had not been well studied. He cautioned that for many people, fasting is simply too difficult and may slow metabolism. A potentially more practical approach is to limit sugar and other processed carbohydrates, replacing them with natural fats, protein and unrefined carbohydrates, he said.

路德维希博士指出,禁食的长期有效性尚未经过充分的研究。他提醒道,对于许多人来说,禁食简直太难了,而且还可能会减缓新陈代谢。他认为,限制糖和其他精加工的碳水化合物,代之以天然脂肪、蛋白质和粗粮,不失为一个更为实际的方法。

“It takes a very disciplined person to skip a couple meals every day,” he added.

“禁食需要人非常自律地每天都有一两餐不进食,”他补充道。

But Dr. Mattson, who has been skipping meals for decades, said the adjustment to skipping breakfast and lunch was a lot like the change that occurs when a couch potato starts exercising.

不过,马特森博士已经坚持了好几十年,他说,不吃早、午饭的适应过程跟懒人刚开始锻炼时很像。

“If you’ve been sedentary for years and then you go out and try to run five miles, you’re not going to feel very good until you get in shape,” he said. “ It’s not going to be a smooth transition right away. It takes two weeks to a month to adapt.”For more fitness, food and wellness news, follow us on Facebook and Twitter, or sign up for our newsletter.

“如果你多年来一直久坐不动,然后突然有一天你想出去试着跑上个5英里(约合8千米),你是不会觉得很舒服的——在你恢复体型之前都会如此,”他说。“改变不是一朝一夕的事儿。你需要两周到一个月的时间来适应。”

“全文请访问纽约时报中文网,本文发表于纽约时报中文网(http://cn.nytimes.com),版权归纽约时报公司所有。任何单位及个人未经许可,不得擅自转载或翻译。订阅纽约时报中文网新闻电邮:http://nytcn.me/subscription/”

相关文章列表