Tryptophan Slump, Debunked!

by Rachel Stuck, RDN

We’ve all experienced it—that sluggish, tired feeling after overdosing on turkey, mashed potatoes, green bean casserole, and an extra buttered roll. The desire to nap after a big Thanksgiving meal has long been blamed on the amino acid tryptophan, which is present in turkey. While there is some truth to tryptophan playing a role in sleepiness, the connection between the tryptophan in turkey and the desire to take a post-meal nap is not as straightforward as you may have been led to believe.

Tryptophan is an essential amino acid found in turkey, other animal proteins, and even some fruits and vegetables. Tryptophan is used by the body for a variety of processes, but its most well-known role is in serotonin and melatonin production.

The graphic below depicts how tryptophan from foods like turkey turns into serotonin, which helps to regulate mood, and melatonin, which helps to initiate sleep. So yes, there is evidence to support the presence of tryptophan in the diet to assist in these processes. However, just including a lot of tryptophan in a meal will not immediately cause you to feel tired.

Here are the facts. Including a variety of tryptophan-rich foods on a weekly basis will support the production of serotonin and melatonin. However, the onset of sleepiness from tryptophan foods is not immediate. The sleepiness after a Thanksgiving dinner may be related to turkey, but it has more to do with the quantity of turkey and other holiday foods loaded onto your plate than the amount of tryptophan ingested. Having a large meal naturally makes you feel sluggish, and if the meal was carbohydrate-dense, you may even feel some brain fog that tricks you into thinking you are tired.

Instead of stuffing yourself to complete fullness, do yourself and your gut a favor this holiday by including mindful eating practices. Eat slowly, savor the flavors, and do your best to balance your plate with plenty of fibrous fruits and vegetables instead of rolls, sweets, and sugary beverages. Refined carbohydrates found in these foods are the real culprits behind the debilitating fullness and sleepiness we feel after a holiday meal.


About the Author

Photo: Rachel Stuck, RDN

Registered Dietitian Nutritionist Rachel Stuck has a background in culinary arts and nutrition counseling. Rachel takes a positive approach to nutrition: she avoids recommending restrictive diets and instead focuses on helping people choose foods that promote health and well-being. She is passionate about empowering and assisting Ixcela members as they develop their unique, gut-healthy lifestyles.

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