为什么有些人怎么吃都不胖？天理何在？

 　　你身边有没有这样的朋友，饭量很大，身材还是保持的超好，简直气死人啊。世界上就有这样的一类人，不管怎么吃都吃不胖。今天用科学给大家讲一下他们到底是怎么回事儿。

　　Everyone knows that guy -- the one who can chug more than his fair share of beer, scarf down an entire pepperoni pizza, grab an ice cream, and make a donut run the next morning, all without gaining a pound.

　　每个人身边都会有这样一个人——吃的比看起来能吃的多，喝下超过他份额的啤酒，狼吞虎咽下一整块意大利腊肠披萨，在抓一个冰淇淋，第二天早上在吃一个甜甜圈，然后体重一磅都不会增加。

　　A new study suggests that people's bodies respond to the same food in very different ways.

　　一项新研究表明，人们的身体对于相同食物的处理因人而异。

　　"If you have two people who are given the same exact diet, they won't necessarily weigh the same." says Dr. Judith Korner, director at the Weight Control Center at Columbia University Medical Center.

　　“如果两个人都吃完全相同的食物，那么他们也不会增长完全相同的重量。”哥伦比亚大学医学中心，体重控制中心的主任Judith Korner博士如是说。

　　1. They've got good genes¹

　　他们有好的基因

　　Not happy with the way your body looks when you stray from your otherwise healthy diet? Blame mom and dad. Dr. Korner says genetics program your "set point," the weight your body strives to maintain. Some people may have a set point at a BMI of 22, while other bodies have a tendency to maintain a BMI of 28 or 30, depending on their genes and hormones²."If you try and alter that set point, your body definitely fights against it," Dr. Korner continues. "There have been studies where you take people of any size, thin or obese³, and if you underfeed them, there are changes in the body that try to get them back to their original weight. It also works the other way too -- the body will try to burn up that extra food to get them back to the set point."

　　已经坚持了健康的饮食对自己的体形还是不满意，那就怪你的爸妈吧。Korner博士说，基因决定了你体重的“基准点”，你的身体会尽量保持在这个基准点。有些人的基准点是BMI(体重指数=体重/身高的平方)22，而有些人的IBM则要达到28或者30，这是他们的基因和荷尔蒙决定的。如果你试着认为调整你的“体重指数“，那你的身体会尽可能的反抗。Korner博士继续说道，“研究表明，不管人们来自哪里，体形，胖瘦如何，如果你不满足身体的需求，那么自身的调节系统会努力把你的体重拉到“基准值”，反之，如果你摄入过多的脂肪，那么身体也会帮助消耗，把你的体重保持在“基准值”。

　　2. Their metabolisms⁵ are at roadrunner levels

　　他们的新陈代谢能力达到公路跑步者水平

　　The formula for weight gain is pretty simple: consume more calories than you burn, and vice⁶ versa. But how many calories you burn daily is much more dependent on your metabolism⁴ than hours spent at the gym. In fact, basic functions, like breathing and circulation, account for nearly three-quarters of the calories you burn daily, and your genetics determine this basal metabolic⁷ rate."[If your friend] is really having many more calories than you are, then his metabolism is probably faster and his body uses up calories much, much more quickly. That's probably how he was born," says Dr. Korner. " (It's like how) some people are born with blue eyes and some with brown eyes."

　　增加体重的公式相当的简单：吃的比你消耗的多，反之亦然。你每天消耗多少卡路里比起在健身房锻炼更其实依赖于你自己的新陈代谢。事实上，人体的基本功能，像呼吸、循环等每天就会消耗你四分之三的卡路里，你的基因决定了你基本的新陈代谢的速率。“如果你的朋友比你摄入了更多的卡路里，但是他的新陈代谢的速度比你更快，那么他消耗的卡路里含量就比要多。这是天生的。”Korner 博士说，“就像有些人的眼睛天生是蓝色的，有些人是棕色的原理是一样”

　　3. They're eating less energy-dense⁸ foods

　　他们少吃高热量的食物

　　A pound of lettuce⁹ may weigh the same as a pound of fried chicken, but they certainly don't have the same effect on the body. That chronically¹⁰ thin friend who's constantly eating might actually be consuming foods that are less caloric than you think, Dr. Korner points out."It can look like someone's eating a lot, maybe they'll have this giant bowl in front of them, but the bowl may contain a salad of beans, chicken, and no dressing," she says. "It looks like they're just chewing and chewing and chewing, but their foods are less energy dense."There are people who say they eat whatever they want without gaining weight -- and they're not lying. While that might conjure¹¹ up feasts of fried chicken, mac & cheese, and cream puffs¹² in your mind, their palates may prefer less-caloric foods, allowing them to eat a much larger quantity.

　　一磅的生菜和一磅的炸鸡，但是他们对身体的影响是不同的。看起来爱吃但一直很瘦的朋友，摄入的食物的卡路里不是你想的那么多。Korner博士指出，“他们看起来感觉吃了很多，面前放那么大一个碗吃饭，但是碗里就只有豆类、鸡肉混合的沙拉，都没有加调味汁。”她说，“看起来他们就一直在不停的吃啊吃，但其实食物中的热量很少。”所有当有人说他们很能吃，但就是吃不胖——（这就是他们吃不胖的原因）他们没有撒谎。当你想象着，他们肯定能吃很多炸鸡、巨无霸芝士汉堡、还有奶油泡芙。事实上他们盘子里都是低热量的食物，所以他们能吃很多。

　　4. They probably don't actually eat that much

　　他们实际上可能吃得并没有那么多

　　Reality is not always as it seems. People tend to eat more and indulge in their favorite foods when they're out with friends, calorie counts be damned. Even if you saw your friend consume more chicken nuggets last night than you eat in six months, their regular diet is likely more modest."I think that it's an exaggeration. They may be eating what they want, but probably the number of calories they're consuming is not huge. If they start eating thousands of calories a day, I think that they would gain weight," says Dr. Korner.The opposite is true too, says Dr. Korner, who has seen patients that claim they've cut calories but still haven't seen the scale budge¹³. Their perceptions of their diets are probably off."If you look at their food diary, you'll see a granola bar, and the patient thought that it was healthy but didn't realize the number of calories in this supposedly healthy granola bar was pretty significant. It's thermodynamically impossible to take in less [than you burn] and not lose weight." The best diet is always the one that works for you, not someone else's plan.

　　事实并不是看起来的那样。当人们和朋友们出去的时候，他们往往会吃的更多，特别是他们喜欢的食物，卡路里自然也会飙升。即使你看见你朋友一次性吃的鸡块比你过去半年吃的还要多，（但你不知道的是）他们平时饮食可能是极其严格。“我想可能有点夸张。他们可能就是吃他们想吃的东西，但是摄入的卡路里没有那么多。如果他们摄入每天数千卡路里，那他们的体重可能会增加，如果情况相反，那体重就会减少”Korner博士如是说，他曾经碰到过病人抱怨，他已经在节食了，但是体重并没有减少。他们觉得自己的节食不起效果了。“但是如果你看他们的饮食日记，你会看见上面写了麦棒，而且病人认为那是健康食品，但是它不知道里面含了多少卡路里，而这点才是最重要的。”最好的饮食是适合你的，而不是（盲目照搬）其他人的饮食计划。

1 genes   

n.基因( gene的名词复数 )

参考例句：

• You have good genes from your parents, so you should live a long time. 你从父母那儿获得优良的基因，所以能够活得很长。 来自《简明英汉词典》
• Differences will help to reveal the functions of the genes. 它们间的差异将会帮助我们揭开基因多种功能。 来自英汉非文学 - 生命科学 - 生物技术的世纪

2 hormones   

n. 荷尔蒙，激素 名词hormone的复数形式

参考例句：

• This hormone interacts closely with other hormones in the body. 这种荷尔蒙与体內其他荷尔蒙紧密地相互作用。
• The adrenals produce a large per cent of a man's sex hormones. 肾上腺分泌人体的大部分性激素。

3 obese   

adj.过度肥胖的，肥大的

参考例句：

• The old man is really obese,it can't be healthy.那位老人确实过于肥胖了，不能算是健康。
• Being obese and lazy is dangerous to health.又胖又懒危害健康。

4 metabolism   

n.新陈代谢

参考例句：

• After years of dieting,Carol's metabolism was completely out of whack.经过数年的节食，卡罗尔的新陈代谢完全紊乱了。
• All living matter undergoes a process of metabolism.生物都有新陈代谢。

5 metabolisms   

n.新陈代谢( metabolism的名词复数 )

参考例句：

• Garden snails are evolving slower metabolisms. 花园蜗牛新陈代谢进化缓慢。 来自互联网
• Elite swimmers tend to be born with certain advantages, such as superefficient metabolisms. 精华的游泳者趋于与某个优点出生，例如superefficient新陈代谢。 来自互联网

6 vice   

n.坏事；恶习；[pl.]台钳，老虎钳；adj.副的

参考例句：

• He guarded himself against vice.他避免染上坏习惯。
• They are sunk in the depth of vice.他们堕入了罪恶的深渊。

7 metabolic   

adj.新陈代谢的

参考例句：

• Impressive metabolic alternations have been undergone during embryogenesis.在胚胎发生期间经历了深刻的代谢变化。
• A number of intoxicants are associated with metabolic acidosis.许多毒性物质可引起代谢性酸中毒。

8 dense   

a.密集的，稠密的，浓密的；密度大的

参考例句：

• The general ambushed his troops in the dense woods. 将军把部队埋伏在浓密的树林里。
• The path was completely covered by the dense foliage. 小路被树叶厚厚地盖了一层。

9 lettuce   

n.莴苣；生菜

参考例句：

• Get some lettuce and tomatoes so I can make a salad.买些莴苣和西红柿，我好做色拉。
• The lettuce is crisp and cold.莴苣松脆爽口。

10 chronically   

ad.长期地

参考例句：

• Similarly, any pigment nevus that is chronically irritated should be excised. 同样，凡是经常受慢性刺激的各种色素痣切勿予以切除。
• People chronically exposed to chlorine develop some degree of tolerance. 人长期接触氯气可以产生某种程度的耐受性。

11 conjure   

v.恳求，祈求；变魔术，变戏法

参考例句：

• I conjure you not to betray me.我恳求你不要背弃我。
• I can't simply conjure up the money out of thin air.我是不能像变魔术似的把钱变来。

12 puffs   

n.吸( puff的名词复数 )；（烟斗或香烟的）一吸；一缕（烟、蒸汽等）；（呼吸或风的）呼v.使喷出( puff的第三人称单数 )；喷着汽（或烟）移动；吹嘘；吹捧

参考例句：

• We sat exchanging puffs from that wild pipe of his. 我们坐在那里，轮番抽着他那支野里野气的烟斗。 来自辞典例句
• Puffs of steam and smoke came from the engine. 一股股蒸汽和烟雾从那火车头里冒出来。 来自辞典例句

13 budge   

v.移动一点儿；改变立场

参考例句：

• We tried to lift the rock but it wouldn't budge.我们试图把大石头抬起来，但它连动都没动一下。
• She wouldn't budge on the issue.她在这个问题上不肯让步。