新陈代谢是你的身体将摄⼊的⻝物转化为能量以维持生命的生化过程。通常⼈们会将新陈代谢的快慢和体重联系起来，认为缓慢的新陈代谢缓是很多⼈减肥困难的罪魁祸首。 

Metabolism is the process your body turns what you eat and drink into energy to maintain life.  Usually people associate the intensity of metabolism to weight loss, blaming slow metabolism  as the culprit of difficulty in losing weight. 

我们对新陈代谢的另外⼀些理解是，⼥性的新陈代谢通常比男性慢；⼀旦更年期到来，它会进⼀步放慢，这就是为什么很多女性在更年期体重开始增加的原因；此外，人的新陈代谢在20多岁时达到顶峰，之后会逐步放慢。

The other common ways we think about metabolism are that women usually have slower  metabolism than men; and it slows down even further once menopause hits, which is why menopause is usually linked to some degree of weight gain for women; also, your metabolism  peaks in your 20s, then slows down after that.

是不是都是真的呢？ 

Are all these true? 

较慢的新陈代谢意味着你燃烧的卡路里比较少，所以更容易储存脂肪。但这真的是有些⼈减肥困难的原因吗？哈佛大学公共卫生学院研究遗传与复杂疾病的教授Chih-Hao Lee博士说，代谢只是部分原因：“现实是，新陈代谢往往起着次要作用。随着年龄的增长，最大的因素往往是不良的饮食习惯和运动不够”。

Slower metabolism means you burn less calories, thus storing more as fat. But is this really the  reason some people have a hard time losing weight? Metabolism is only partially to blame,  says Dr. Chih-Hao Lee, professor of genetics and complex diseases at Harvard's T.H. Chan  School of Public Health, “The reality is that metabolism often plays a minor role. The greatest factors as you age are often poor diet and inactivity.”

女性的新陈代谢真的比男性慢吗？根据《科学》杂志最近发表的⼀篇论文，事实并非如此，至少在原因上和大多数⼈认为的不同。

Do women have slower metabolism than men? According to a paper recently published by  Science, that is not really true, not in the same sense believed by most people. 

《科学》杂志的这篇名为“⼈类生命中的每⽇能量消耗” 的论⽂有80位合著者，收集了6个实验室40多年的研发信息，查看了近6500人，年龄从8天到95岁的数据。他们发现，在控制了体型和肌肉量后，男性和⼥性的新陈代谢率并没有什么不同。肌⾁⽐脂肪组织燃烧更多的能量，所以肌⾁量更多的⼈燃烧卡路⾥也就更多。因为通常男性身体的脂肪较少，肌⾁较多，所以⼈们总是认为女性新陈代谢较慢。

The paper in Science titled “Daily energy expenditure through the human life course” has 80  co-authors with combined efforts of half a dozen labs collected over 40 years. It looked at the data of almost 6500 people, ranging in age from 8 days to 95 years. They found that  men and women don’t really have different metabolism rates, after controlling for body size and  the amount of muscle. Muscle burns more energy than fat tissues, so people that have more  muscle mass burn more calories. Because usually men have less body fat and more body  mass, so people tend to believe women have a slower metabolism. 

更年期会进⼀步减慢女性的新陈代谢吗？你很可能会这么想，但这个论⽂在研究了数据之后完全没有这样的结论。是的，年龄是新陈代谢率的决定性因素，但更年期并不是⼀个重要的里程碑。事实上，就新陈代谢而言，所有的⼈都有着这四个不同的阶段：

Does menopause further slows down a woman’s metabolism? You may tend to think so, but  the study just did not see that in the data. Yes, age is a determining factor in your rate of  metabolism, but menopause is not such a critical milestone. In fact, all people of all ages, have  four distinct stages as far as metabolism goes:

1. 婴儿期，直到1岁，这时候卡路⾥的燃烧达到顶峰，比成⼈的平均水平高出约50%。

2. 从1岁到20岁，新陈代谢每年减慢约3%。

3. 从20岁到60岁，非常稳定。

4. 60岁以后，新陈代谢每年下降约0.7%，直到95岁时整体下降约20%。

1. Infancy, up till the age of 1, when calorie burning is at its peak, about 50% above the  average adult rate. 

2. From 1 to 20, metabolism slows by about 3 percent a year. 

3. From 20 to 60, it is pretty steady. 

4. After 60, metabolism declines by about 0.7% a year, until reaching approximately 20%  decline by the age of 95.‍

所以，把你中年开始不断扩大的腰围归咎于新陈代谢的减慢是没有道理的。真正的里程碑是20岁和60岁。

So all that blame on slower metabolism for your expanding waist line in the middle age is not  justified. The real milestones are age 20 and 60. 

如果你的⽬标是加快新陈代谢，那么⼀定要加强锻炼，尤其可以考虑高强度间歇训练（HIIT）。研究表明，在HIIT运动之后，你的新陈代谢在运动结束后还可以保持很⻓时间，可以长达⼀天，这就是所谓的“后燃效应”。

If boosting metabolism is your goal, physical exercise is a sure bet, especially High Intensity  Interval Training. Studies have shown that, after a period of HIIT exercise, your metabolism can  stay revved up long after the exercise is over, for up to one day, which is called “the afterburn  effect”.  

锻炼肌⾁也可以促进新陈代谢，因为更多的肌⾁质量意味着燃烧更多的卡路⾥。摄入⾜够的蛋白质和力量训练在这个方面对你会有帮助。

Building muscle can also boost metabolism as more muscle mass means more calories burned. Having enough protein intake and strength training will help you build up more  muscles. 

媒体上几乎所有的⼈都在告诉你“要加快新陈代谢”，而且很多饮食和减肥产品都在宣称可以帮你做到。但是，更快的新陈代谢真的应该是我们所有人的⽬标吗？新陈代谢真的是越快越好吗？

Wherever you look, everybody is telling you to “speed up your metabolism” and every diet and product is marketed to do so. But should a faster metabolism be everybody’s goal? Is it really the faster the better? 

乔尔·福尔曼（Joel Fuhrman）医生认为事实正好相反。福尔曼医生是⼀名获得委员会认证的家庭医生。他因为擅长通过营养预防和逆转疾病而出名。他也是七次《纽约时报》的最畅销书作家。 

Dr. Joel Fuhrman thinks the opposite is true. Dr. Fuhrman is a board-certified family physician.  He is mostly known for his specialty and research on preventing and reversing disease through nutrition. He is also a seven-time New York Times best selling author. 

在这个每个⼈都想加快新陈代谢的年代，福尔曼医生认为这是因为人们都希望可以吃很多东西而不会发胖。然而，从衰老的角度来看，实际上你应该希望自己的新陈代谢速度尽可能慢，因为我们衰老的速度就是我们新陈代谢的速度，它们是⼀致的。那些天生新陈代谢就⽐较慢的⼈很可能在衰老方面具有着先天的优势。

While a lot of people try to speed up their metabolism in this day and age, Dr. Fuhrman thinks  people do that so they can eat a lot food without putting on extra pounds. However, from an  aging perspective, you actually want as slow metabolism as possible, because we age at the  rate of our metabolism. Those people who genetically have a slower metabolism may actually  have an advantage with aging. 

所以，如果你想活得更久，更健康，减慢新陈代谢才应该是你的⽬标。要做到这⼀点，福尔曼医生说，你要避免频繁进⻝的习惯，试着限制你的卡路里摄⼊量（不要吃得太饱，以素食为主），晚饭吃得早⼀点，空腹上床，每天晚餐和第二天早餐之间间隔约13个小时。

So slowing down your metabolism should be your goal if you want to live longer and healthier.  To do that, Dr. Furhman said, you want to avoid the habit of frequent eating, try to limit your  calorie intake (not eat too full, and mostly plant-based), have an early dinner, go to bed with an  empty stomach, and have a daily window of about 13 hours between dinner and breakfast. 

那运动呢？运动不是会大大加快新陈代谢吗？

How about exercise then? Doesn’t exercise rev up your metabolism big way? 

福尔曼医生是不反对运动的，他说：“运动是加速新陈代谢而不加速衰老的唯⼀途径”。

Turns out he does not oppose to exercise at all: “Exercise is the only way to speed metabolism without accelerating aging”.