With Thanksgiving on everyone’s mind these days, there is often just as much talk about the turkey itself as there is about the gathering together of family and friends. Every year, people seem to dwell on the notion that the big dinner makes us sleepy, and the finger of blame is inevitably pointed at the star of the meal, the turkey.

Turkey contains an amino acid called tryptophan. Our bodies need a certain amount of tryptophan for building proteins, as is the job description of most amino acids. This one, however, also is utilized in a multi-step process of making serotonin, a neurotransmitter in the brain that helps regulate sleep. But before we go and blame the delicious main dish for our inability to stay awake for the second half of the football game, a few more details may provide greater insight into exactly what is happening inside our bodies after having enjoyed this traditional meal.

While any big meal prepared with foods containing tryptophan can cause sleepiness, it seems the real culprits are all those carbohydrates we consume on Thanksgiving, in the form of potatoes, stuffing, vegetables, bread and pie. The overload of carb-heavy calories stimulates the release of insulin, which in turn triggers the uptake of most amino acids from the blood into the muscles except for tryptophan.

Once all those other amino acids have been swept out of the bloodstream, tryptophan from any source (turkey, chicken or even cheddar cheese) has an easier time making its way to the brain, where it produces serotonin. Without the insulin surge from the ingestion of carbohydrates, tryptophan would have to compete with all the other kinds of amino acids in the big meal as they make their way to the brain. In that case, we might be justified in blaming the turkey for our post-meal lethargy. However, since few guests around the table are able to turn down those delicious side dishes, we have to consider these other sources as potential reasons for our sleepiness.

Chemistry aside, we have the ability to combat the brain’s natural reaction to the meal just consumed. A brisk walk around the neighborhood, even in the chill of the late November air, can do wonders to energize and invigorate a sluggish brain. Once your food settles, toss around a football in the backyard. Help clear the table and package up leftovers. Or, start making your holiday gift list. After all, everything will soon be on sale…and power shopping is great exercise.

Cathleen Kronemer is a longtime fitness instructor at the Jewish Community Center.