Those that feel tired after Thanksgiving are likely experiencing food coma, a condition MerriamWebster.com defines as the “colloquial term for the sleepiness or drowsiness that follows a large meal.”  

Usually, the tryptophan in turkey is blamed for the post-Thanksgiving meal drowsiness, the Texas Medical Center (TMC) says on its website tmc.edu.  Yet, Adam P. Knowlden, an associate professor of health science at the University of Alabama, contends such association may not be entirely warranted.  

“Tryptophan does have a role to play in helping to induce the sleep wake cycle,” he says. “However, unless you’re deficient in it nutritionally, it’s probably not going to make much of a difference.” 

Knowlden says most people consume enough tryptophan—whole milk and canned tuna are just some of the foods that have more tryptophan than turkey, TMC also says on its website— making it unlikely that it’s only the turkey that’s making people tired. He says it’s likely that all of the foods that’re eaten on Thanksgiving—not just one—provide the perfect recipe for feeling sleepy afterwards.  

“One of the main reasons we may feel sleepy after a Thanksgiving feast is we are eating carbohydrate-rich foods like mashed potatoes and stuffing along with our turkey,” he says. “A large meal causes an insulin spike in our bodies.” 

Consequently, the post-Thanksgiving meal drowsiness “is more likely the result of blood being diverted from throughout the body, including the muscles and brain, to the stomach for digestion,” according to registered dietitian Judith Rodriguez.  

To limit the feelings of fatigue, Kim Sasso, a registered and licensed dietitian, recommends several tips to limit food consumption on Thanksgiving. She suggests eating breakfast and lunch on Thanksgiving to help avoid overeating at dinner time, restricting food and beverage intake on the holiday to seasonal dishes (e.g., eat pumpkin pie instead of mashed potatoes) and consuming as many vegetables and fruits as possible. “Eating vegetables doused in cream sauce and butter is better than not eating any at all,” she contends. 

Knowlden has his own theory on what makes people tired on Thanksgiving that also shifts the blame away from tryptophan.  

“Those who have large meals and being able to have a breather don’t have [as much] stress, anxiety and daily,” he explains. The large meal consumers “are able to mentally relax, and that helps them feel that they have the time to destress and therefore, are able to get into a sleep sleepy or state.”   

Jaycee Miller is a freelance researcher, blogger and writer living in New Jersey.