One of the more curious phenomena of the Thanksgiving meal is how we can feel completely full, yet somehow always find room for dessert.
Our ability to eat a ridiculous amount of food on Thanksgiving Day is related to the sheer variety of foods typically offered on a holiday table. Variety excites the appetite.
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.”
Over the years, Dr. Rolls has asked countless adults and children to fill up on savory foods like chicken or sausages. When offered a second serving, study subjects were often too full to eat much more. But when they were then presented with cookies, bananas or raisins, they always had room for another bite.
“It’s a change in your hedonic response to the food you’ve just eaten,” said Dr. Rolls, referring to the pleasure we get from eating. “If you’ve had a lot of salty and savory foods, the sweet foods might get more pleasant.”
Fast-forward to the modern Thanksgiving table, and you begin to understand why, on the fourth Thursday of November, so many of us become eating machines. After filling up on a few rounds of turkey, mashed potatoes and stuffing, chances are you’ll feel quite full. But when the pumpkin pie with whipped cream comes around, your brain will sense an entirely different kind of food, and suddenly, you’ll find yourself reaching for pie.
But don’t worry. While sensory specific satiety allows you to keep eating new foods, eventually your body will tell you to stop eating. After about 1,500 calories in one sitting, the gut releases a hormone that causes nausea.
Notably, the satiety signal is particularly strong in children and diminishes with age. In studies by Dr. Rolls, children were allowed to eat unlimited quantities of M&Ms. But once they were full, they had a strong response to being offered more. “These little kids said, ‘These taste yucky — I don’t like them anymore,.’” Dr. Rolls said. “We’d never seen as strong a response in adult subjects.”
The reason for the pronounced difference in response by age isn’t clear, Dr. Rolls said. It may have to do with a natural decline in sense of smell and appetite as we get older. Or it could be that a lifetime of eating highly processed foods interferes with our natural satiety signals.
The main consequence of eating a big Thanksgiving meal is the need to unbutton your pants. (Recently on the “Milk Street” podcast, the culinary historian Yolanda Shoshana recommended a “pajama” Thanksgiving to solve that problem.) Indigestion and flatulence are also common hazards of holiday eating. In rare cases, the extra digestive workload can temporarily raise the risk for a heart attack or gallbladder problems, so people with underlying cardiovascular disease should take care to avoid overdoing it.
The biggest downside of this variety effect is that food makers have taken notice. It’s the reason marketers have created variety packs and bundle multiple foods together in “value meals.”
“It’s of great interest to food companies who want to sell you more food and get you to eat more food,” Dr. Rolls said. “But you can also engineer your eating environment to have this work for you. Nobody wants to eat a half a plate of broccoli, but if you fill half your plate with a variety of vegetables and fruits, in that case, variety is a good thing.”
More from the Well Newsletter
Try this mindfulness exercise at your holiday meal
Mindful eating is not meditating on food — it’s simply pausing and bringing full awareness to the experience. Today you can combine mindful eating with a gratitude practice you can share with the whole family.
1. Pause before eating, and think about the incredible journey of your meal.
Take a few minutes to look at the spread before you. Contemplate everything and everyone it took to bring the meal to your table. Think about those who planted and harvested the ingredients, the farmer who raised the turkey, the drivers who carted it all to the store and the grocery workers who put the food on the shelves and rang up your purchase. Think about the person or people who prepared the food in your home.
Take one more moment and think of the cultural traditions, handed down over generations, that brought this food to your plate. You can silently express your gratitude for the opportunity to enjoy delicious food and the companions you’re enjoying it with. Or even better, read this mindfulness exercise out loud, and invite others at the table to contemplate the enormous effort required to bring so much delicious food to a single table.
2. Bring all your senses to the meal. Now eat! Try to be attentive to color, texture, aroma and even the sounds that different foods make as you eat them.
3. Take small bites. It’s easier to taste food completely when your mouth isn’t full. Put down your utensils between bites.
4. Chew thoroughly. As you chew your food, try identifying all the ingredients, especially seasonings. Chew well until you can taste the essence of the food.
Here’s a bonus mindful eating exercise:
How to Be Mindful While Eating Chocolate
Take a gratitude photo
For a fun family activity, ask everyone today to take a gratitude photo. Pick one thing that feels special and meaningful to you and take a picture. It can be something in your home, a special food on the holiday table, or something you spotted outside during your walk. Share your photos with family members and friends as you’re enjoying dessert.
“We have cameras with us all the time, and we often take pictures habitually without a whole lot of intention,” said Jaime Kurtz, a professor of psychology at James Madison University whose research has shown the benefits of gratitude photos. “Mindful photography is about slowing down. It’s not just snapping mindless photos. It’s keeping an eye out for something that is beautiful or meaningful to you.”
Get a head start on inexpensive holiday gifts
My favorite gift guide, of course, is the 2021 Well Holiday Gift Guide. Check it out if you missed it. The big winner in our 2020 gift guide was the Women’s Bean Project, which offers bean and lentil soup mixes, snacks and even dog treats, all made by women who had been chronically unemployed.
Lately, I’ve been doing a lot of holiday browsing with the help of several gift lists from Wirecutter, a product review site owned by The New York Times. I’ve got my eye on a collapsible popcorn bowl from 77 best gifts for under $25. I also found an advent calendar of beauty items for my college student. You’ll find gift guides by price, for children of different ages, last minute gifts and gifts for co-workers. There’s even a guide for the perfect Santa hat.
Find the gift ideas you’re looking for:
Holiday Gift Guides from Wirecutter
The Week in Well
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