Turkey is not the only culprit for drowsiness on Thanksgiving

There are many traditions that families hold dear during the holidays, including a post-Thanksgiving-meal nap. While most people assume that the tryptophan in turkey is the culprit, a registered dietitian at Baylor College of Medicine says it is a combination of factors.

"Tryptophan is an essential amino acid that is required by the body because it cannot synthesize from other amino acids," said Kristi King with Baylor and Texas Children's Hospital. "It is found in poultry, milk, chocolate, oats, cheese and even some seeds."

According to King, the amount of tryptophan that is found in turkey is the exact same as any other poultry.

"One reason people may get sleepy after their Thanksgiving meal is that the turkey is usually consumed with other foods that contain tryptophan, typically carbohydrates. It could be a cumulative effect causing drowsiness," King said.

Overeating in general is another factor, according to King.

"When we eat a large meal, blood rushes to the gut to help transport the newly digested macro and micronutrients. With the blood focusing on the gut, it can cause less blood availability for the rest of the body, including the brain, which can cause light-headedness or invoke that tired feeling," she said.

King said that the best bet for Thanksgiving is to follow the MyPlate method: fill half of your plate with colorful vegetables, a quarter of your plate with carbohydrates and the other quarter of your plate with turkey or other proteins.

"Drink alcohol in moderation and drink plenty of water to stay hydrated. Dehydration can also cause sleepiness," King said.

Planning family physical activities after a meal is a good way to stay awake and stay moving.