The common wisdom at Thanksgiving is that the amino acid tryptophan, found in turkey, is responsible for the sleepy feeling one gets after the big meal. Well, new research completed at the University of Cambridge focused on the post prandial effects of different macronutrients has found it may be the carbohydrates, rather than the proteins in meals, that make us more lethargic and less efficient calorie burners. The research, published in the scientific journal Neuron, has implications for understanding obesity and sleep disorders.
Wakefulness and energy expenditure rely on “orexin cells”, which secrete a stimulant called orexin hypocretin in the brain. Reduced activity in these unique cells results in narcolepsy and has been linked to weight gain. By highlighting these cells with genetically targeted fluorescence in mouse brains, and then introducing different nutrients such as amino acid mixtures similar to egg whites, while tracking orexin cell impulses, the researchers found amino acids stimulate orexin cells. Previous work by the group found that glucose blocks orexin cells (which was cited as a reason for after-meal sleepiness), and so the researchers also looked at interactions between sugar and protein. They found that amino acids stop glucose from blocking orexin cells (in other words, protein negated the effects of sugar on the cells).
So, the implications of this research are, if you’re trying to stay focused on the road after the big meal, cut down on the potatoes, dressing and pie and go for the turkey, ham and oysters at Thanksgiving dinner. In addition, this research suggests you consider replacing the donut, sugary cereal and sweet roll at your daily breakfast meal before work or school and eat more of the protein foods like eggs, ham, milk and cheese to be the most efficient and focused throughout the day.