On today’s page of Talmud, the great talmudic sage Abayye describes his insatiable appetite. He would leave one house full, and arrive at another hungry.
מגילה ז,ב
אֲמַר אַבָּיֵי: כִּי נְפַקִי מִבֵּי מָר, הֲוָה שָׂבַעְנָא. כִּי מְטַאי לְהָתָם, קָרִיבוּ לִי שִׁיתִּין צָעֵי דְּשִׁיתִּין מִינֵי קְדֵירָה, וַאֲכַלִי בְּהוּ שִׁיתִּין פְּלוּגֵי. וּבִישּׁוּלָא בָּתְרָיְיתָא הֲווֹ קָרוּ לֵיהּ צְלִי קֵדָר, וּבְעַאי לְמִיכַּס צָעָא אַבָּתְרֵהּ.
Abayye said: When I left the house of the master, Rabba, to go to Marei bar Mar, I was already satiated. However, when I arrived there at Marei bar Mar’s house, they served me sixty plates of sixty kinds of cooked dishes, and I ate sixty portions from each of them. The last dish was called pot roast, and I was still so hungry that I wanted to chew the plate afterward.
Abayye suggested two explanations for his appetite. Perhaps he was just more hungry than he realized, and so arrived ready to eat some more. Or perhaps there is just always room for dessert.
אָמַר אַבָּיֵי, הַיְינוּ דְּאָמְרִי אִינָשֵׁי: כָּפֵין עַנְיָא וְלָא יָדַע. אִי נָמֵי: רַוְוחָא לִבְסִימָא שְׁכִיחַ.
And in continuation Abayye said: This explains the folk saying that people say: The poor man is hungry and does not know it, as Abayye was unaware how hungry he had been in his master’s house. Alternatively, there is another appropriate, popular expression: Room in the stomach for sweets can always be found.
Rashi explained Abayye’s phrase this way:
רווחא לבסימא שכיח - ריוח מצוי לדבר המתוק בתוך המעיים
There is always room in the digestive system for something sweet
Of course there is. Who hasn’t finished an enormous Shabbat dinner, only to unexpectedly find room for a fantastic looking dessert? Hey, we’ve all been there.
“One of the more curious phenomena during the holiday season is how we can feel completely full after a big meal, yet somehow always find room for dessert ”
Sensory Specific satiety
It turns out that there is a scientific reason why there is always room for dessert. It is because of what is called sensory specific satiety. This is a sensory hedonic phenomenon that refers to the declining satisfaction generated by the consumption of a certain type of food, and the consequent renewal in appetite resulting from the exposure to a new flavor or food. In 2001 Hollie Raynor and Leonard Epstein from the university of Buffalo published a seventeen page review paper on the topic. It looked at over twenty studies in rats and some thirty studies in children (underweight, normal weight and obese) and included observations like this:
When participants were served a snack of either a highly liked flavor of ice cream or a variety of flavors of ice cream, with the same energy density across all flavors, female participants and male and female participants consumed significantly more grams of ice cream in the variety than same condition.
And
Meals consisting of different types of sandwiches (e.g., tuna, roast beef, cheese, egg) or snack foods (e.g., pizza, sausage roll, egg roll), as compared with meals of just one of these foods, produce significantly more consumption during the meal.
(The ice cream studies and meals with different sandwiches were performed on human volunteers, not rats.) Here is how The New York Times explained it:
This “variety effect” is an evolutionary adaptation that served us well during pre-buffet times. Imagine if your ancestors binged on buffalo meat and then stumbled across a patch of ripe berries — but everyone was too full to eat them. Skipping dessert in that scenario would mean missing out on a stash of important nutrients. (And if that had happened, you probably wouldn’t be reading this now.)
The mechanism that allows us to make room for dessert is called sensory specific satiety, which means that the body has different limits for different foods as a way to help ensure a balanced intake of nutrients. Barbara Rolls, a professor and the director of the Laboratory for the Study of Human Ingestive Behavior at Pennsylvania State University, has been studying sensory specific satiety since the early 1980s.
“It’s the reason most of us manage to eat a balanced diet even if we don’t have nutritional knowledge,” Dr. Rolls said. “Variety is our friend in terms of nutritional balance.”
And so, when, after a large delicious meal, you are served dessert and somehow find room for it, you should know that you are in good company. Rats, together with our human ancestors who binged on buffalo meat and the great Abayye all did the same.
“Animal and human research has shown that when a variety of foods are provided during an eating bout, there is an increase in consumption of food.”
