Why you get tired after Thanksgiving dinner. Hint: it’s not Tryptophan.

Really the only thing that doesn't make you sleepy

You know the story. Have thanksgiving dinner in the middle of the afternoon, eat right up until you start to feel sick (and maybe a little more), and then find a couch or chair and fall half-asleep. If it happens, it's likely that someone will blame it on the Turkey. The old myth is that Turkey contains the amino acid tryptophan, which causes drowsiness. None of that is actually false. Turkey does contain tryptophan. And tryptophan is related to sleep – it is the only amino acid that can be converted to serotonin, which regulates our sleep patterns. But take a look at this list. Pork, chicken, and peanuts all have as much or more tryptophan as turkey. And beef and eggs are comparable too. But you don't hear people complaining that they are falling asleep because of the chicken sandwich they had for lunch. So what does make you sleepy at 6pm on Thanksgiving? The answer is: carbs. Think about the rest of the stuff on your plate: mashed potatoes, stuffing, cranberry sauce, breads, sweet potatoes, pie… maybe some vegetables (but who really eats those?). Most of what you eat at thanksgiving is carbohydrates. And the research shows that high carbohydrate meals cause sleepiness by releasing insulin, which releases much more serotonin than you get from the tryptophan in turkey. So now, thanks to my help, when someone at your thanksgiving dinner tomorrow claims they are falling asleep due to the turkey, you can be the annoying nerdy guy who tells them they are wrong. Or just have another piece of pie.