We can stop the mythical complaints: turkey does not make you tired after Thanksgiving Dinner. It has just as much tryptophan as other meat. In fact, red meat has slightly more.
What makes you tired after turkey dinner is the sheer amount of food you ate and the culturally expected proportion of that this is carbs—and the high-glycemic kind at that.
With all those carbs, the regular amount of tryptophan in turkey gets shuttled into the brain unlike usual, triggering conversion to serotonin and then melatonin: the sleep hormone. So the insulin spike may make you feel groggy regardless, but with a higher than normal spike and plentiful amount of meat, Thanksgiving Dinner takes you out.
Tryptophan content of foods From highest to lowest
P.S. As a warning, you probably don’t ever want to eat sea lion with a high carb meal like Thanksgiving. Or any carbs for that matter. It’s over double the amount of tryptophan in our typical meats. I don’t know what would happen but it probably wouldn’t be pretty if you planned on being active or chipper at all in the next 24 hours.