Your hormones and Thanksgiving

The Science Behind the Feast

Well, it’s that time of the year again. Thanksgiving, a day filled with family, gratitude, and a lot of food. For many, it’s a holiday where indulgence takes center stage. But beneath the surface of turkey and pumpkin pie lies a fascinating physiological orchestra. Every bite you take triggers a cascade of hormonal signals and metabolic processes, designed to help your body manage the feast. In this blog, I explore how your hormones react to the indulgences of Thanksgiving, how they shape your experience of the day, and what you can do to stay balanced while enjoying the festivities.

The Build-Up: Anticipation and Hunger Hormones

As Thanksgiving approaches, if you are the lucky one in charge of the planning, cooking, and social interactions your cortisol level may spike. Known as the stress hormone, cortisol helps you manage the demands of the holiday. While short-term spikes in cortisol can boost energy and focus, prolonged stress can take a toll on your health, making it essential to manage pre-holiday tension through relaxation techniques and aerobic exercises.

The excitement doesn’t just stop with planning. When you see and smell the rich aromas of roasting turkey and baking pies, your brain releases dopamine, the “reward hormone.” This creates a sense of pleasure and anticipation, priming you for the feast. At the same time, your stomach produces ghrelin, the “hunger hormone,” which signals your brain to increase appetite. This hormone is responsible for those growling stomachs and mouth-watering moments as you wait for the meal to begin.

The Feast Begins: Insulin and Blood Sugar Surges

When you finally dig into the meal, carbohydrates from mashed potatoes, stuffing, and cranberry sauce are quickly broken down into glucose. This causes your blood sugar levels to rise, prompting the pancreas to release insulin (if you have a good reserve of pancreatic beta cells). Insulin helps transport glucose from the bloodstream into your cells, where it’s used for energy or stored for later.

Thanksgiving meals are often heavy on carbs, leading to a rapid spike in blood sugar. While insulin works to bring those levels back down, the quick rise and fall can leave you feeling lethargic. This phenomenon, often called a “food coma,” isn’t just about overeating—it’s your body’s natural response to a heavy meal.

Turkey and Tryptophan: A Sleepy Myth

Turkey often gets blamed for post-meal drowsiness due to its tryptophan content. Tryptophan is an amino acid used by your body to produce serotonin, a mood-regulating neurotransmitter, and melatonin, the sleep hormone. However, turkey doesn’t contain significantly more tryptophan than other meats. The real reason you feel sleepy is likely the combination of overeating and insulin’s effects on your blood. As insulin helps your cells absorb nutrients, it increases the availability of tryptophan for serotonin production, contributing to a relaxed, sleepy state.

The Fullness Factor: Satiety Hormones at Work

As you eat, your stomach begins to stretch, triggering the release of hormones that signal fullness. Cholecystokinin (CCK) and glucagon-like peptide 1 (GLP-1) released by the small intestine, slow digestion and promote satiety. Meanwhile, leptin, a hormone produced by fat cells, tells your brain you’ve had enough to eat. These signals are designed to help you stop eating, but the variety of flavors and textures on a Thanksgiving table can override these mechanisms. This is known as sensory-specific satiety—when the availability of diverse foods tempts you to keep eating, even when you’re full.

Post-Meal Metabolism: Digestive Hormones and Cortisol

After the meal, your digestive system continues to work hard. Hormones like glucagon-like peptide-1 (GLP-1) and peptide YY (PYY) are released to slow gastric emptying and help you feel full. However, if you’ve overindulged, these signals can take longer to kick in, leaving you feeling uncomfortably stuffed.

Large meals also temporarily increase cortisol levels, as your body works to manage the caloric overload. For individuals with diabetes or insulin resistance, this can pose additional challenges, as the body struggles to regulate post-meal blood sugar.

Gratitude, Connection, and Feel-Good Hormones

Thanksgiving isn’t just about food—it’s also a day for connection and gratitude. Spending time with loved ones and reflecting on what you’re thankful for can boost oxytocin, the “love hormone.” Oxytocin reduces stress, promotes feelings of connection, and enhances your overall sense of well-being. This hormonal response to social bonding can make the holiday not only enjoyable but also beneficial for your mental health.

Seasonal Rhythms and Appetite

As it falls in late November, Thanksgiving is a time when seasonal hormonal changes can influence appetite and stress levels. Shorter daylight hours and colder temperatures increase glucocorticoids (stress hormones), which may heighten food-seeking behavior. At the same time, sensitivity to leptin, the satiety hormone, can decrease, making it harder to feel full. Coupled with higher levels of ghrelin, these changes may naturally encourage larger meals and indulgence during the holiday season.

The Long-Term Perspective: One Day vs. Consistency

While one indulgent meal won’t significantly impact your health, habitual overeating or late-night feasting can lead to long-term issues like insulin resistance, type 2 diabetes, and hypertension. The key is to enjoy Thanksgiving in the context of an overall balanced lifestyle. A single day of indulgence, when paired with healthy habits throughout the year, can be a joyful celebration without lasting negative effects. For me, an early morning, good, long run on Thanksgiving day allows me to enjoy the feast a lot more, and without feeling guilty.

Tips for a Hormone-Friendly Thanksgiving

• Pace Yourself: Eating slowly allows your satiety hormones time to signal fullness.

• Balance Your Plate: Include lean proteins, fiber-rich vegetables, and healthy fats to stabilize blood sugar levels.

• Limit Portions: Serve yourself smaller amounts of each dish to enjoy a variety without overindulging.

• Stay Active: A post-meal walk can help lower blood sugar and improve digestion.

• Practice Gratitude: Reflecting on what you’re thankful for boosts oxytocin and enhances your emotional well-being.

A Celebration of Science and Tradition

Thanksgiving is a beautiful blend of tradition, gratitude, and indulgence. It’s a time to savor good food and the company of loved ones while marveling at the incredible complexity of your body’s hormonal responses. By understanding how your hormones react to the feast, you can make thoughtful choices that support both enjoyment and health.

So, this Thanksgiving, as you pass the stuffing and slice into the pie, take a moment to appreciate the symphony of hormones that make it all possible. Here’s to a joyful, balanced, and hormonally harmonious holiday!

Happy Thanksgiving!