為什么與朋友聚餐會暴飲暴食？

How well do you remember the dinners you enjoyed with your friends, the ones where you left feeling as if you had eaten more than you could manage? Or in the opposite direction, the meals where you didn’t order a pudding, because nobody else did?

你可曾記得你和朋友一起享用晚餐時每次都吃得很撐?或恰恰相反，你和別人一起用餐時沒有點布丁，僅僅是因為別人也沒有點?

Perhaps you can blame social cues for eating too much or too little. Several decades of research shows that we eat more in company, and we follow what and how others eat.

或許，你可能把吃得太撐或沒有吃飽怪罪于餐伴。幾十年的研究表明，與朋友一起吃飯會讓人胃口大開，而且我們用餐時會容易隨大流。

But how exactly do our companions affect what we eat, and can we tap into these social influences to cut down on fats and sugar, and even lose weight?

不過，我們的用餐同伴究竟是如何影響著我們的飲食?我們又能否利用這些餐桌社交影響來減少脂肪和糖的攝入，甚至達到減肥的目的?

A series of diary studies by health psychologist John de Castro in the 1980s alerted us to social influences in eating. By 1994, de Castro collected diaries of over 500 people recording their meals and the social context of how they ate them – in company, or alone.

健康心理學(xué)家德卡斯特羅(John de Castro)在20世紀80年代進行的一系列日記研究告訴我們，要警惕社交對飲食的影響。截至1994年，德卡斯特羅收集了500多人的日記，記錄他們的膳食以及他們在何種環(huán)境下用餐——同他人聚餐或是獨自用餐。

To his surprise, people ate more in groups than when they were by themselves. Experiments by other scientists also found that people ate 40% more ice-cream and 10% more macaroni and beef in company than when alone. De Castro named the phenomenon ‘social facilitation’ and described it as the “single most important and all-pervasive influence on eating yet identified”.

讓他感到驚訝的是，人們在聚餐時比獨自用餐時吃得多。其他科學(xué)家的實驗也發(fā)現(xiàn)，相較于獨自用餐，人們在聚餐時多吃了40%的冰淇淋，及10%的通心粉和牛肉。德卡斯特羅將這一現(xiàn)象稱為"社交助長作用"，并將其形容為"對飲食一項最重要和最普遍的影響，但作用尚待確定"。

What expands our palate when we eat with someone else? Hunger, mood, or distracting social interactions were all discounted by de Castro and other scientists. Studies reveal that we extend our meal times when we eat in a group, and we eat more in those extra minutes.

是什么讓我們在和他人一起用餐時會胃口大開?在德卡斯特羅和其他一些科學(xué)家看來，饑餓、情緒或分散注意力的交談都不是主要原因。研究表明，我們在多人聚餐時會延長用餐時間，于是給我們更多時間吃更多東西。

Careful observation in a range of eateries showed that bigger groups do enjoy longer meals. And when meal time is fixed, larger parties no longer eat more than smaller ones. In a 2006 experiment, scientists gathered 132 people and gave them either 12 or 36 minutes to eat cookies and pizza. The participants ate alone, in pairs or in groups of four. Within each specific meal time, participants ate similar amounts regardless of their party size. This lab experiment provided one of the strongest evidence that longer meal time is key to larger meal sizes in social eating.

仔細觀察一批餐館發(fā)現(xiàn)，聚餐人數(shù)越多用餐時間也就越長。與此同時，如果限制用餐時間，人數(shù)多的聚餐并不會比人數(shù)少的聚餐吃得多。2006年，科學(xué)家們召集了132個人進行實驗，讓這132個人在12分鐘或36分鐘內(nèi)吃餅干和披薩，他們或獨自、或兩人一組、或四人一組用餐。在每個固定的用餐時間內(nèi)，不論人數(shù)多少，吃的東西數(shù)量都差不多。這項實驗為社交聚餐吃得多少取決于用餐時間長短提供了一個最強有力的證明。

It seems very plausible that when we dine with our friends, we might linger, and therefore reach for yet another slice of cheesecake.

和朋友們一起用餐時，我們很可能會磨蹭拖延時間，這樣就能多吃一塊芝士蛋糕。

When we anticipate a group meal, we even order more food individually. This was revealed from observations in an Italian restaurant: the larger a dining party, the more pastas and desserts each diner ordered. Social meals appear to make us hungrier, and it appears that we decide that we will indulge even before we order. Such observations led C Peter Herman, a food scientist, to propose his ‘feast hypothesis’: indulgence is part and parcel of social meals, and that we socialise partially so that we can all eat more without the guilt of overindulgence.

當我們預(yù)知是和幾個朋友一起吃飯時，我們甚至也會給自己多點食物。我們在一家意大利餐廳觀察發(fā)現(xiàn)：聚餐人數(shù)越多，點的意大利面和甜點也越多。社交聚餐似乎讓我們感到肚子更餓，而且我們似乎還沒點餐就決定要放縱一把。食品科學(xué)家赫爾曼(C Peter Herman)基于這一現(xiàn)象提出了"盛宴假設(shè)"的理論：放縱自己是社交聚餐的一部分，吃飯也是為了社交，這樣就算吃得更多我們心里也不會有過度放縱的負罪感。

Furthermore, the joys of eating together could be felt even if our companion is not real. In a Japanese study, individuals were asked to eat popcorn alone either in front a mirror or an image of a wall. Those who ate before a mirror enjoyed the popcorn more. Have you ever noticed how many restaurants have prominent mirrors?

而且，我們即使不是跟真的同伴一起吃飯，也能感受到同人一起吃飯的樂趣。日本一項研究發(fā)現(xiàn)，參與研究的人被安排獨自對著鏡子或?qū)χ鴫Τ员谆?。那些對著鏡子的人吃的爆米花較多。說到這里，你可曾注意到有多少餐廳在室內(nèi)安裝了引人注目的鏡子?

But sometimes we do eat less in a company. Our drive to indulge can be tamed by the need to behave. We could manage our impression by eating according to social norms; or we might observe how others are eating and follow their lead, a behaviour called social modelling.

但有時候我們在與同伴聚餐時反而吃得較少，因為這時放縱的欲望會受到我們想要良好表現(xiàn)的壓制。我們想要通過符合社會規(guī)范的飲食來管好自己的形象;或許我們可能會觀察別人是如何吃東西然后仿效。這種行為稱為社交示范。

There are plenty of examples. Studies showed that obese children ate less in groups than when they ate alone. Overweight youths ate more chips and cookies when accompanied by an overweight youth but not when they ate with someone of normal weight. In university cafés, women ate fewer calories with men at their table, but ate more in women-only groups. And across the US, diners ordered more desserts when served by heavier waiters.

這種例子有很多。有研究顯示，肥胖兒童與人聚餐時比獨自用餐時吃得較少。超重的青少年如果和也是超重的同伴在一起會吃更多的薯片和餅干，但是當他們與正常體重的同伴一起時就不會大吃特吃。在大學(xué)的咖啡館里，女生和男生一起吃飯時攝入的熱量較少，但是和女生同伴們在一起時就吃得較多。在美國各地餐廳，如果服務(wù)員體重過胖，食客們就會點更多的甜點。