Ah, Thanksgiving. A time for family, football, turkey and afternoon naps.
A lot of people think an amino acid in turkey, called tryptophan, makes you tired after the big meal. But that idea is, um, a turkey.
It is true that tryptophan, taken in very substantial quantities on an empty stomach, can cause drowsiness. But truth be told, there’s just not that much tryptophan in turkey. The amount in turkey is the same, per weight, as beef or chicken. There’s twice as much tryptophan in parmesan cheese — or caribou. There’s four times as much tryptophan in eggs.
So if we’re not eating scrambled eggs with caribou for Thanksgiving, why do we get tired? Could it be because Aunt Ethel’s stories are just boring?
The real answer is that we’re eating a crap load of food. On average Americans eat a whopping 3,500 calories during a Thanksgiving meal. That’s a lot of turkey, gravy, stuffing, mashed potatoes, yams, sweet potatoes, cranberries, casseroles and pie.
When we eat all that good stuff our body, in response, pumps out a bunch of insulin to aid the digestive process. The insulin, in turn, stimulates the production of two chemicals associated with drowsiness, serotonin and melatonin. Thus we feel the impulse to find a couch.
Those two chemicals, by the way, are also associated with happiness. Makes sense to me: a full belly, football on the TV and a lazy afternoon make me very happy indeed.