You know the feeling. You finish a full meal and are like...
你懂那種感覺。吃完一整盤食物後，覺得...
I'm never eating again.
我飽到炸裂了。
But then, out comes a beautiful piece of cake. And, well...
但眼前出現一塊精緻的蛋糕。然後...
You said you were full!
你不是說你飽了!
Not for dessert.
甜點不算啊。
Turns out you really can "make room" for dessert. And there's a scientific reason why. The thing that gives you room for dessert is called "sensory-specific satiety." Sa...satie...satiety?
結果，人真的可以為了甜點「留胃」。而且這是有科學根據的。你之所以還吃得下甜點，是因為有「特定感覺飽足感」。飽...飽...飽足感？
Satiety. It's one of those words...
飽足感。就是這樣唸...
That's Dr. Barbara Rolls. She's a nutritional scientist, and she's been studying sensory-specific satiety since the '80s.
這位是 Barbara Rolls 博士。她是營養學專家，從 1980 年代開始研究特定感覺飽足感。
It's a really important, basic, and very reproducible finding about human eating behavior.
這種人類的進食習性很重要且基本，實驗結果也可以反覆驗證。
Dr. Rolls says it's why we often misunderstand that "full" feeling. So, to see it in action, we ran an experiment similar to one she's done before. We gave six people a giant plate of mac and cheese.
Rolls 博士說這就是為什麼我們常會有「飽了」的錯覺。為了親眼證實，我們模仿了博士之前做過的實驗。我們找來六個人，一人給一大盤起司通心粉。
Wow, that is a lot of macaroni and cheese!
哇，好多起司通心粉!
And told them to eat until they were full.
然後叫他們吃到飽為止。
I'm done.
我飽了。
And then, for the second course, we gave them...more.
接著第二道菜，我們端出...更多的通心粉。
No!
不!
I'm not happy with this experiment.
我不喜歡這個實驗。
Then, on a different day, we did it all over again.
然後過幾天，再從頭做一遍。
I'm getting full.
我快不行了。
Except, this time, after they were full, we gave them ice cream.
但這一次，他們吃飽後，我們給的是冰淇淋。
Ice cream.
冰淇淋。
Yes.
好耶。
Oh, yeah, I'm done.
好了，我吃不下了。
On average, after they said they were full on mac and cheese, each person could eat just one more ounce of it in their second serving.
平均來說，他們表示吃飽之後，每個人只能再吃下一盎司的通心粉。
I got a solid two bites in.
我吃了整整兩大口。
But when we gave them ice cream instead, somehow they could eat three times as much. They made room for dessert. The experiment shows that when you feel full, it's not necessarily that your stomach is physically full; it's more about how interested you are in eating more.
但如果換成冰淇淋，他們可以吃整整三倍的量。他們真的有留胃給甜點。實驗顯示當飽足感出現時，並不一定表示肚子真的沒空間了；比較像是沒有想吃更多的慾望。
Sensory-specific satiety is that change in how much you like a food, how much of a food you want to eat as you're eating it.
特定感覺飽足感是在描述你對食物喜好的改變、進食過程中對分量接受度的改變。
And to really show that, we asked our participants to rate, on a scale of 10, their interest in mac and cheese before their first course...
為了量化結果，我們請受試者在吃通心粉之前，用一到十分表示自己想吃的程度...
Probably, like, a six.
或許六分吧。
Five.
五分。
I love macaroni and cheese, so... About 25!
我超愛起司通心粉，所以...25 分!
...and after.
...接著是吃完後。
I can't eat anymore.
我再也吃不下了。
Probably, like, a one.
可能一分。
Yeah, zero.
耶，零分。
They all started pretty interested in the mac and cheese. But after their first course, they were less interested. Even less so after their second helping. But we also asked them throughout the experiment to rate their interest in ice cream. And even after getting full on mac and cheese, they stayed interested. The only thing that made them lose interest in ice cream was having ice cream.
每個人剛開始都很想吃通心粉。但吃完一份後，就比較沒興趣了。吃完第二份後更是興趣缺缺。但我們在實驗途中也有問他們對冰淇淋的渴望程度。即使再也吃不下通心粉了，他們還是想吃冰淇淋。等到真的吃下了冰淇淋後，興趣才會下降。
"I've just had enough of that food; I want something else." is really what sensory-specific satiety is.
「我吃膩那樣食物了；我想換個口味。」這就是所謂的特定感覺飽足感。
And that instinct has a purpose: It's meant to keep us healthy.
這種本能是有目的的：為了讓我們保持健康。
So, it's a good thing. We're omnivores, and we need to eat a variety. So, it's gonna help to guarantee that you're going to eat the variety of nutrients that you need.
這是好事。我們是雜食性動物，需要多樣化的飲食。它會確保你攝取所需的各種營養。
It also means that there are certain situations where it makes us extra susceptible to overeating.
這也表示某些情況下它會容易讓我們吃太多。
It can backfire though, of course. Because if we are presented with a variety of food, it encourages us to keep eating.
當然，它也會造成反效果。因為要是我們眼前有很多種食物，它會鼓勵我們一直吃。
Ever eat too much at a buffet? Or on Thanksgiving? Yeah, me too. That's because when we have a lot of variety, we stay interested in eating for longer.
曾經在吃到飽餐廳吃太飽？或是感恩節時？我也有過。那是因為食物選擇很多時，我們可以吃得比較久。
This change in the appeal of foods during a meal keeps us going, keeps us eating.
不同食物所造成的新鮮感讓我們一直吃，吃不停。
In another experiment, Dr. Rolls gave different four-course meals to two groups. One where every course was the same food, and one where every course is very different. The people with different foods ate 60 percent more.
在另一個實驗中，Rolls 博士給了兩組人馬不同的四品套餐。一組吃四道完全一樣的菜，另一組則有四道不同的菜可以吃。吃不同食物的那組多吃了百分之六十。
Sensory-specific satiety is why you'll eat more french fries with condiments than without, why you'll eat more ice cream if you get multiple flavors than just one. It's also why kids will eat more veggies if they can eat a variety of them together than if they only have one option.
特定感覺飽足感解釋了為什麼薯條加醬就可以吃更多，以及冰淇淋口味越多就可以吃越多。也解釋了為什麼一次給小孩多種蔬菜，比只給一種還吃得多。
That's interesting! And it only took me eating a ridiculous amount of mac and cheese to learn it.
太有趣了!而且我才吃這麼一大堆起司通心粉就懂了呢。
- 「親眼證實、眼見為憑」- see something in action
So, to see it in action, we ran an experiment similar to one she's done before.
為了親眼證實，我們模仿了博士之前做過的實驗。
