The Science Behind Holiday Eating

I didn’t even like the pie. It was too sweet and store-bought. Still, there I was—standing barefoot in the kitchen, fork in hand, jeans already unbuttoned, eating it straight from the plastic container. I wasn’t hungry, but I was still eating.

The holiday kitchen is its own ecosystem—spices in the air, the familiar clutter of dishes, the hum of a full house. We eat past the point of hunger, not out of need, but out of something else. Memory. Instinct. Permission.

Every year, by New Year’s Day, the shame spiral kicks in. I’m left googling “sugar detox,” pricing out gym memberships, and trying to erase the previous three weeks like they were a stain on my progress. I’d spent the last year following a strict training plan—running four miles a day, tracking macros, staying committed to keto. I knew how to stay “on track” and override cravings.

So why, every winter, did my body—and my resolve—seem to abandon the plan?

Humans’ Biological Wiring Tells Us to Feast During the Holiday Season

Ancient rituals honoring the winter solstice centered on feasting and togetherness. The Romans celebrated Saturnalia, which marked the coming winter months and involved an abundance of food and gifts. In early Germanic societies, Yule was a mid‑winter festival spanning multiple days that honored the solstice and welcomed the inevitable gradual return of light. In my Caribbean-American home, it wasn’t a solstice log or a Roman banquet—it was Trinidadian Parang, a Christmas musical celebration dating back to the eighteenth century. Our feast includes indulging in a traditional lime-infused eggnog called punch de crème and meat-filled cornmeal pies called pastelles.

For most of human history, winter wasn’t just cold—it was dangerous. Food was hard to come by. Energy needed to be conserved. When food was available, we ate it. Not because we were undisciplined, but because survival required it. We evolved in environments of scarcity and unpredictability—what evolutionary biologists call a “feast-or-famine” model. We feasted when conditions allowed.

Despite the abundance of modern food, our biochemistry hasn’t kept pace. Less light exposure during the winter months shifts your biological clock, throwing off your hormones, mood, and sleep. One of those hormones, serotonin, also drops. Because serotonin is the neurotransmitter that fuels feelings of happiness, having less of it can contribute to low mood. Fatigue is another symptom. This is known as seasonal affective disorder (SAD), or seasonal depression. SAD may create a stronger draw toward carbohydrate‑rich, comforting foods—and weight gain.

According to a 2023 study, our food and energy intake increases in spring and winter but decreases in summer. Changes in how much food we eat or desire are due to environmental changes (fewer daylight hours) and social influences—like holidays.

Ambient temperature also affects how much we eat. Colder temperatures increase ghrelin levels (the hormone that makes us feel hungry) and decrease leptin (the hormone that signals feelings of fullness), making us hungrier in the winter. When it’s hot out, leptin production increases, and we eat less.

These biological responses may still influence our cravings and energy‑storage instincts: craving warmth, calories, and rest may be as much biology’s winter survival plan as modern psychological comfort‑seeking. So when I grew ravenous in the winter, my body wasn’t betraying me. It was remembering biology.

Modern Diet Culture versus Ancient Wisdom 

Modern wellness culture tends to treat indulgence like a crime scene. The most obvious example? The “cheat day.” A concept that promises freedom but is built entirely on the idea that pleasure is dangerous unless tightly scheduled. It’s a momentary lifting of restrictions—then back to penance—as if food needs a hall pass.

A 2025 review suggests that cheat days can lead to an unhealthy relationship with food.

Christy Harrison, a registered dietitian and author of The Wellness Trap, argues that wellness and diet culture intersect, ultimately robbing people of their well-being. Our dissatisfaction with our bodies, coupled with a toxic relationship with food, is due to a culture that depicts food as something to earn, fear, or justify. What looks like permission is often just control, dressed up as reward.

During my own health journey, I leaned hard into that logic. A slice of birthday cake meant an extra sprint the next day. Mac and cheese at Friendsgiving? Only if I’d front-loaded with salad the week before. These weren’t decisions based on celebration. They were transactions. Controlled indulgence wrapped in justification. And still, it never really worked the way I wanted it to.

The problem wasn’t the food. It was the framing.

The modern “feast” is shame-adjacent and digitally documented. We scroll past plates and captions. We track our intake. We read headlines about guilt-proof recipes and plan our penance before the dessert fork drops. But when you strip away the macros, cheat days and ancient feasts aren’t so different. Both interrupt restriction. Both follow structure. Both mark a deviation from the everyday. The key difference? Ancient feasts were communal. Intentional. Emotional. They weren’t followed by shame—they were followed by storytelling.

Ancient cultures made room for the feast—and understood its role in resilience. Modern diet culture isolates it, labels it a failure, and markets the fix.

We don’t need another day of atonement. We need to remember why the feast existed in the first place.

Not every craving is about calories. Some are about company, or memory, or needing something warm and familiar to take up space in your body when the rest of the world feels cold.

Research shows that communal eating increases satisfaction and enhances emotional well-being. On the contrary, according to a 2021 study, eating alone, specifically when you don’t actually want to be alone but are forced to do so because you live alone, can fuel depression.

Kelly McGonigal, health psychologist and author of The Joy of Movement, writes that food is often our most immediate tool for self-soothing. But shame, especially around food, cuts us off from the very things that nourish us emotionally. “Shame isolates us from others and from ourselves,” she writes. “But joy reconnects. Movement, music, shared meals—these are things that bring us back.”

In community, I forget to be afraid of food. When I’m telling stories over a plate, not tracking every bite, the anxiety lifts. The numbers fall away. The feast becomes what it’s always been: a way back to ourselves.

It took me years to understand that I wasn’t undoing progress during the holidays. I was participating in a pattern, one my ancestors already knew. These days, I still train. I still run. I still eat with intention. But I no longer treat December as something to survive or erase. I build space around the feast—not as a break from discipline, but as part of it.

If I know I’m going to a holiday dinner, I don’t starve myself beforehand or punish myself after. I don’t try to “balance the macros” or “earn” the cake. I eat the food because it’s meaningful. I’m not erasing anything. I’m joining something.

I stack my plate with the things I know will support me—turkey, ham, maybe oxtail if I’m lucky. But now I leave room for the mac and cheese too.

So no, I’m not detoxing in January. I’m not apologizing for what I ate, or trying to scrub my body clean of memory. I’m not doing penance. I’m practicing recognition.

And that pie I didn’t like? I wouldn’t eat it again. But I don’t regret it either.

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