We've all been there.. too much food on Thanksgiving, and you end up falling asleep.. only to wake up to the sound of a football game in the background.

You have probably heard that it’s all due to the tryptophan in the turkey, which can make people feel tired.

But it’s not really just the turkey that is making you tired!

On average, Americans consume 3,000 to 4,000 calories and more than 229 grams of fat on Thanksgiving – eek!

Of course, those numbers depend on someone’s family, social situation and how hungry they are on the big day. However, it’s easy to reach that number with all the traditional dishes, plus a few alcoholic beverages throughout the course of the afternoon and evening.

As your body works to digest the massive amount of food, blood is pulled away from your brain, to help burn and digest the calories, fats and carbs you just ate. This causes your body to slow down and go into a bit of what we can call a system overload, according to Kelli Groth, a registered Pediatric Dietician at Providence Health Care.

Plus, you have to consider that the late afternoon is already a time many of us feel drowsy just on regular days! So adding a big meal in the same time frame probably isn’t helping.

Getting back to the tryptophan in the turkey, which is a natural sedative and amino acid. It has been blamed for years for our sudden sleepiness after Thanksgiving dinner.

Dr. Devon Grant, a researcher at the Sleep and Performance Center at Washington State University, Spokane confirmed it is very unlikely we get tired after eating turkey because tryptophan does not act on the brain unless you eat very large quantities of turkey on an empty stomach.

It's highly unlikely you have a very empty stomach when you sit down to eat on Thanksgiving. Grant said the lazy feeling is more of a cumulative thing: the larger, late afternoon meal, compounded with alcohol, creates a great environment to feel sleepy.

A dietician from Rockwood Multi-Care Health System, Jen Ropp, said tryptophan is actually found in all animal products, including poultry but also egg whites and dairy. In fact, Ropp said chicken and some cheeses actually contain higher levels of the sedative.

So don’t blame the bird when you’re not feeling up to washing the dishes!

