Thanksgiving is a great time of year to connect with family and friends, eat turkey, and ... nap. If after eating turkey you feel ready to fall asleep midsentence like Dorothy in the field of poppies in the famous scene in The Wizard of Oz, it may not be due to the L-tryptophan, an essential amino acid in the turkey that has the effect on your brain of a sleep drug. In fact, L-tryptophan is actually used as a sleep aid for people and animals since it converts into serotonin in the brain, but that is not the whole story of why you want to crash after eating, according to the latest research.

While you may have heard of L-tryptophan, you may not know why it makes someone nod off so effectively, or why it may not be fully to blame for your food-coma reaction to eating turkey and all the trimmings on Thanksgiving. L-tryptophan (also called, simply, tryptophan) is an essential amino acid, meaning your body can't make it from building blocks and needs you to get it from food sources. Tryptophan is one of 20 naturally occurring amino acids —which are the building blocks of proteins – so you need it, just not too much of it.

Since too much of a good thing is never a great idea, if the purpose of eating is to feel energized, not knocked out, you may want to know which foods have L-tryptophan and how much you need to get in a day for optimal health. Here's everything you need to stay awake this Thanksgiving, and enjoy the post-feast activities.

What is L-tryptophan and why does it make you sleepy?

L-tryptophan is an essential amino acid that your body needs in order to make melatonin and serotonin, both of which relax the brain and help you calm down and get sleep. When L-tryptophan hits the brain it gets converted into these neurochemicals, which is one reason that tryptophan in large doses helps to promote sleep. Melatonin helps regulate the sleep-wake cycle, and serotonin helps regulate mood,  sleep, appetite, and pain.

According to one study, a dose of just 1gram of tryptophan taken 45 minutes before bed is enough to help you go to sleep. The reason people like tryptophan for sleep is that it "will decrease the time taken to fall asleep in those with mild insomnia and in those with a long sleep latency," according to the research, which means you can wake up fresh the next day.

One six-ounce serving of turkey breast has 488 milligrams of tryptophan which is more than your Recommended Daily Amount (RDA) for tryptophan, but still much less than the dosage that people take to go to sleep.

So, before making the assumption that tryptophan in turkey is why you're in a post-Thanksgiving food coma, you need to know exactly how tryptophan works in the body and consider the fact that small amounts of tryptophan are also good for you, and necessary. It helps your body perform vital functions including regulating metabolism, and when eaten with other nutrients like iron, the body uses it to create vitamin B3 for a healthy metabolism.

Your body needs tryptophan for healthy metabolism

Tryptophan can also help your body make the vitamin niacin, also known as B3, which helps your body regulate energy and metabolism and your cells need B3 for healthy functioning, according to research. But in order for your liver to turn tryptophan into this important vitamin, it needs to also have iron, riboflavin, and vitamin B6.

So to help your body turn tryptophan into B3, the best bet is eating turkey in conjunction with apples, bananas, and pomegranates, which are rich sources of iron, as well as legumes, nuts, and seeds, beetroot, as well as citrus fruits, since vitamin C helps you absorb iron.

For riboflavin add in mushrooms and for vitamin B6 add soybeans, oats, peanuts, and wheat germ as well as bananas. When you combine your foods, in other words, the body has more vitamins and minerals to assemble the vital nutrients it needs to stay energized.

Foods that contain tryptophan

Before you think that sticking to a plant-based menu will help you not OD on L-tryptophan, know that this essential amino acid is found in both plant and animal-based proteins. A little goes a long way, however, and you don't need to seek it out, since most people consume two to three times the RDA of tryptophan which is 250 to 425 milligrams a day.

As Americans, we are already getting 900-1000 milligrams per day, which is more than the body needs to fulfill the necessary daily tasks of building muscle and regulating metabolism and growth. A six-ounce serving of turkey breast has 488 milligrams of tryptophan – or the equivalent of more than your daily requirement.

Foods with tryptophan.* The RDA is 250 to 410 mg/day

  • six ounces of ground turkey contains 612 mg of tryptophan
  • 1 six-ounce skirt steak (beef) contains 636 mg of tryptophan
  • 1 cup of firm tofu has 592 mg of tryptophan
  • 1 cup of roast chicken has 507 mg of tryptophan
  • 1 filet of fish as 570 mg of tryptophan
  • 1 cup of cooked soybeans (edamame) has 416 mg of tryptophan
  • 1 cup of milk has 100 mg of tryptophan
  • 1 ounce of cheese has 91 mg of tryptophan
  • 1 ounce of chia seeds has 124 mg of tryptophan
  • 1 ounce of flax seeds has 84 mg of tryptophan
  • 1 ounce of cashews has 75 mg of tryptophan
  • 1ounce of pistachios has 74 mg  of tryptophan
  • 1 ounce of peanuts has 65 mg of tryptophan

*All values according to

Is it the turkey or are carbs making you sleepy?

Scientists have studied turkey and tryptophan and are convinced that the amount in the turkey, and how it plays out in the body, is not the main culprit when it comes to your post-prandial urge to nap. Another factor is the overload of carbohydrates that usually comes with the Thanksgiving menu since studies show that carbs make you sleepy.

You've heard of the "sugar rush" but the opposite is true: Sugar puts you down. In one study, the researchers found that  "carbohydrate consumption lowers alertness within 60  minutes after consumption." Additionally, within just 30 minutes of consumption, carbs increased fatigue.  The authors stress that eating sugar to boost mood is a myth. So rather than blame the turkey, look warily at the mashed potatoes.

Johns Hopkins points out that for L-tryptophan to make you sleepy it has to be present without other amino acids, which is not the case when you eat turkey. Amino acids are the building blocks for the proteins that build up your muscles and other cells in the body.

Over-eating contributes to your sleepiness

According to the Johns Hopkins researchers, another reason we get tired after a big Thanksgiving dinner is that we eat more than the body needs, sending blood flow to the stomach and digestive tract to work harder than usual, which deprives our brains of oxygen, making you feel as sleepy as sitting at the rear of a full airplane where little airflow is circulating. For ideas of how to not want to go lie down after your big meal, try these suggestions from the experts at Hopkins.

5 Ways to avoid that post Thanksgiving tired feeling

1. Eat small portions and avoid having too much sugar, candy or processed foods, since your body can best digest food if it gets a little at a time, not seconds of the stuffing and mashed potatoes to metabolize all at once.

2. Add more vegetables to your plate than anything else. Eating fiber-filled vegetables and skipping the starches or sugars (like the marshmallow topping on the sweet potato casserole) will help your digestive system slow down the number of calories absorbed, which helps keep blood sugar from spiking and falling. By regulating blood sugar you keep insulin in check and store less fat.

3. Slow down. It's a social day and easy to wolf up your entire plate of food without even thinking about it, but by slowing down, and letting your fork sit on the plate for a minute before eating more bites, your body has a chance to catch up with your intake and send cues that you are full, and don't need more food. It can take 20 minutes for your gut to signal to the brain: "Basta!" As in, No more, please. Are the eyes still hungry? Wrap up the seconds and extras to take home.

4. Drink plenty of water. Your food is calorie-dense, and drinking water can help slow down digestion and absorption to allow your stomach and gut to catch up with the incoming fuel. Drinking water also helps your brain distinguish between thirst and hunger.

5. Instead of turkey bring a main or side dish that's vegetable-based.  Instead of turkey, try making a delicious mushroom-and-bean-based Vegan Wellington, or if you're not able to take the time to cook this year, bring home a vegan turkey alternative that will allow you to participate in the festivities and skip the comatose post-meal feeling. Here are the best store-bought vegan turkey roasts to choose from.

Bottom Line: Turkey Isn't the Only Thing Making You Sleepy on Thanksgiving

L-tryptophan, an essential amino acid in turkey, converts into serotonin in the brain, but it's not the only food that is making you want to take a nap after your big Thanksgiving feast. All those carbs may be partly to blame. You need some tryptophan in your diet, but not too much. Here's what to eat instead.

For more ideas of foods to cook and eat instead of turkey on Thanksgiving check out The Beet’s Vegan Holiday Recipes to find more festive, plant-based dishes that will impress everyone at your Thanksgiving table.

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