Happy holidays! It’s a special time of year about family. And food.  And fatigue. And if your holiday meal includes turkey, you may be among those who have long felt the fatigue culprit is the tryptophan in turkey.  But listen up folks, the turkey may have been getting a bad rap.

Most likely, it’s the whole traditional holiday meal that can produce that after-dinner lethargy. The meal is quite often heavy and high in carbohydrates — from mashed potatoes, to bread, stuffing and pie — and your body is working hard to digest that food. After all, the average holiday meal contains 3,500 calories, and if you drink alcohol with your dinner, you’ll likely feel its sedative effect, too.

High-carb, high-fat and high-sugar foods (like, say, buttery mashed potatoes and pumpkin pie) trigger a neural response as soon as they hit the small intestine. That response, in what’s called the parasympathetic nervous system, tells our body to slow down and focus on digesting rather than go out and seek more food.

Then there’s your brain.  More specifically, a group of brain cells called orexin neurons are very sensitive to glucose levels, which spike after a big meal. Those neurons produce a protein, orexin, which moderates wakefulness in the brain.

But orexin isn’t the only sleep-related neurohormone affected by food. As the quantity of food increases, so too does the amount of insulin released as a normal part of the body’s digestion. The insulin, in turn, increases the amount of serotonin and melatonin that flood the brain, two chemicals associated with drowsiness.

And if that’s not enough, if you’ve traveled for the holidays, shifts in your schedule, stress or even slight jet lag can take their toll regardless of what you’re eating.  Add to that a few hormonal shifts that happen in the body after a chow down, and you’ve got a recipe for food coma.

So, if you’d rather not snooze off, and miss any of the day’s festivities, what can you do to counteract the lethargy of the big feast?  Unfortunately, not a lot will counteract it; there’s no real way to avoid a sleep response to a big meal.  But you can prevent it by reducing the overall amount you eat and lowering fat, refined carbohydrates and sugar in the first place.

If you’re not willing to compromise on your holiday meal, simply enjoy, and try a leisurely walk outdoors afterwards, rather than sprawling out on that oh-so comfy couch.  Enjoy your holiday!