为什么有些人怎么吃都不胖？

Theyve got good genes.

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 hormones. “If you try and alter that set point， your body definitely fights against it.”

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BMI则要达到28或者30，这是他们的基因和荷尔蒙决定的。如果你试着调整你的“体重指数”，那你的身体会尽可能地反抗。

Dr Korner continues， “There have been studies where you take people of any size， thin or obese， 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.”

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回原来的水平，反之，如果你摄入过多的脂肪，那么身体也会帮助你消耗掉，使你的体重保持在‘基准值。”

Their metabolisms are at road runner level.

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 vice versa. But how many calories you burn daily is much more dependent on your metabolism 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 metabolic rate.

增加体重的公式相当简单：吃的比你消耗的多，反之亦然。比起在健身房锻炼你每天消耗多少卡路里，其實更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速率。

“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. Thats probably how he was born，” says Dr Korner. “（Its like how）some people are born with blue eyes and some with brown eyes.”

“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你消耗的卡路里含量要多。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。”

Theyre eating less energy dense foods.

他们高热量的食物吃得少。

A pound of lettuce may weigh the same as a pound of fried chicken， but they certainly dont have the same effect on the body. That chronically thin friend whos constantly eating might actually be consuming foods that are less caloric than you think， Dr Korner points out. “It looks like someones eating a lot， maybe theyll 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 theyre just chewing and chewing and chewing， but their foods are less energy dense.”

一磅的生菜和一磅的炸鸡一样重，但是它们对身体的影响是不同的。Korner博士指出，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得那么多。“他们看起来吃了很多，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地吃啊吃，但其实食物中的热量很少。”

There are people who say they eat whatever they want without gaining weight—and theyre not lying. While that might conjure up feasts of fried chicken， mac&cheese， and cream puffs in your mind， their palates may prefer less-caloric foods， allowing them to eat a much larger quantity.

所以當有人说他们很能吃，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。

They probably dont 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 theyre 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.

事实并不是看起来的那样。当人们和朋友们出去的时候，他们往往会吃得更多，特别是吃他们喜欢的食物，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）他们平时饮食可能极其严格。

Word Study

metabolism /m?'t?b?l?z?m/ n. 新陈代谢

chronically /'kr?n?kli/ adv. 长期地;慢性地;习惯性地

conjure up 使……呈现于脑际;使想起

That smell always conjures up memories of holidays in France.

indulge /?n'd?ld?/ v. 沉湎;沉迷;沉溺（于……）