為什么有些人怎么吃都不胖？

Theyve got good genes.

他們有好的基因。

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.”

已經(jīng)堅持了健康的飲食對自己的體形還是不滿意，那就怪你的爸媽吧。Korner博士說，基因決定了你體重的“基準(zhǔn)點”，你的身體會盡量保持在這個基準(zhǔn)點。有些人的基準(zhǔn)點是BMI（體重指數(shù)=體重/身高的平方）22，而有些人的BMI則要達(dá)到28或者30，這是他們的基因和荷爾蒙決定的。如果你試著調(diào)整你的“體重指數(shù)”，那你的身體會盡可能地反抗。

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博士繼續(xù)說道：“研究表明，不管人們來自哪里，體形，胖瘦如何，如果你不滿足身體的需求，那么自身的調(diào)節(jié)系統(tǒng)會努力把你的體重拉回原來的水平，反之，如果你攝入過多的脂肪，那么身體也會幫助你消耗掉，使你的體重保持在‘基準(zhǔn)值?！?/p>

Their metabolisms are at road runner level.

他們的新陳代謝能力達(dá)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.

增加體重的公式相當(dāng)簡單：吃的比你消耗的多，反之亦然。比起在健身房鍛煉你每天消耗多少卡路里，其實更依賴于你自己的新陳代謝。事實上，人體的基本功能，像呼吸、循環(huán)等每天就會消耗你四分之三的卡路里，你的基因決定了你基本的新陳代謝速率。

“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.”

“如果你的朋友比你攝入了更多的卡路里，但是他的新陳代謝的速度比你更快，那么他消耗的卡路里含量就比你消耗的卡路里含量要多。這是天生的?！盞orner博士說，“就像有些人的眼睛天生是藍(lán)色的，有些人是棕色的原理是一樣。”

Theyre eating less energy dense foods.

他們高熱量的食物吃得少。

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雞一樣重，但是它們對身體的影響是不同的。Korner博士指出，看起來愛吃但一直很瘦的朋友，攝入的食物的卡路里不是你想得那么多。“他們看起來吃了很多，面前放那么大一個碗吃飯，但是碗里就只有豆類、雞肉混合的沙拉，都沒有加調(diào)味汁。”她說，“看起來他們就一直在不停地吃啊吃，但其實食物中的熱量很少。”

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(dāng)有人說他們很能吃，但就是吃不胖——（這就是他們吃不胖的原因）他們沒有撒謊。當(dāng)你想象著他們肯定能吃很多炸雞、巨無霸芝士漢堡，還有奶油泡芙，事實上他們盤子里都是低熱量的食物，所以他們能吃很多。

They probably dont actually eat that much.

他們實際上可能吃得并沒有那么多。

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.

事實并不是看起來的那樣。當(dāng)人們和朋友們出去的時候，他們往往會吃得更多，特別是吃他們喜歡的食物，卡路里自然也會飆升。即使你看見你朋友一次性吃的雞塊比你過去半年吃的還要多，（但你不知道的是）他們平時飲食可能極其嚴(yán)格。

Word Study

metabolism /m?'t?b?l?z?m/ n. 新陳代謝

chronically /'kr?n?kli/ adv. 長期地;慢性地;習(xí)慣性地

conjure up 使……呈現(xiàn)于腦際;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……）