The Science
Thanksgiving meal can be a major road block when seeking a healthy lifestyle and can be the catalyst that sends your diet spiraling out of control during the holiday season. Let's take a closer look at the science behind our beloved Thanksgiving meal and see if we can find a healthier path through the maze of stuffing, sweet potatoes, and of course, turkey.
Speaking of turkey, there is no better place to start when breaking down the traditional meal. Most people have a preference when asked the age old question, "White or dark meat?", but what constitutes this difference?
White meat, traditionally found in the breast and wings of the turkey is made up of explosive, powerful muscle tissue. Turkeys have the ability to fly but they spend most of their time strutting on the ground, only using their wings in times of emergency. Because of this, they have developed the same muscle composition in their wings that we would expect to see in a power lifter. It is poorly vascularized (receives a relatively small blood supply) because it is more adept at burning glycogen (the type of sugar or carbohydrate stored in your muscles) for energy. Because of this adaptation, the muscle does not rely on the supply of energy from the blood. No blood = white coloring. White meat is very lean (low fat content) and thus has fewer calories than dark meat.
As you might expect then, the dark meat (found predominantly in the legs and thighs) is so colored because of its vascularity. These red muscle cells are of the same composition that we would expect to find in a runner's legs. A turkey spends all day strutting on the ground and endurance activities require a large blood supply to replenish the muscles energy source and oxygen (aerobic respiration requires oxygen). Dark meat, having a higher fat content, yields more calories, but also has higher levels of vitamins and minerals
Another common talking point for this holiday bird is known as tryptophan. L-Tryptophan is an essential amino acid found in turkey and is often said to make you sleepy. L-Tryptophan is responsible for producing niacin (a B-vitamin), serotonin, and melatonin. The last two complexes are neurotransmitters that elicit a calming effect and help regulate sleep. What most people don't know, however, is that there is a comparable amount of L-tryptophan in foods such as chicken, pork, and cheese.
Now that we've covered the protein in you thanksgiving meal, let's cover the carbohydrates and fats in the meal. Carbohydrates (anything that breaks down into sugar when digested) are extremely bountiful at this particular meal table. Dinner rolls, mashed potatoes, casseroles. You name it, it's on the table. All these carbs stimulate the pancreas to secret insulin into your blood. Insulin is an extremely powerful substance that causes a number of important reactions in your body. One of these important reactions shuttles amino acids into muscle cells, amino acids that would normally be competing with L-tryptophan for uptake. This action increases the relative concentration of the compound in your blood stream and promotes the synthesis of serotonin, thus causing drowsiness. Likewise, fats can also make you feel drowsy but for a completely different reason. Fats are slow digesting and require a lot of energy to breakdown. For this reason, blood flow is diverted from other areas of your body and directed towards the gut to help with the digestion process. The diversion of resources causes energy levels to decrease after a meal rich in fats.
Now let's cover the final two aspects of the Thanksgiving meal, over-eating and alcohol consumption. Just like with fats, over-eating diverts blood flow to the gut to help with digestion. The large amount of food we tend to consume on holidays requires a lot of attention from our body, leaving our nervous system low on energy. Alcohol can compound the issue if you, like many, choose to partake during the thanksgiving meal. Alcohol is a central nervous system (CNS) depressant which leads to that sleepy feeling.
The Tips
Now that we've broken down the science behind our favorite feast, what can we take away to help avoid some of these pitfalls?
- Exercise - Over-eating is common practice during this holiday. Why not boost your metabolism an hour or so before your feast with a quick cardio routine or high intensity interval training. Elevate your heart rate for at least 30 minutes to obtain a lasting boost to your metabolism. Any type of exercise will help, but high intensity cardio increases your metabolism the most.
- White or Dark Meat? - White meat has less fat and fewer calories. Dark meat has higher fat content (albeit mostly healthy mono- and polyunsaturated fats) and a higher concentration of vitamins and minerals. Normally the decision would be rather trivial but when adding all the other food consumed with this meal, the lower calorie white meat makes a difference. Also, avoid skin to cut even more calories.
- Drowsiness - L-Tryptophan may play a small role in your after-dinner snooze fest but the real culprits here are over-eating and carbohydrates. This sleep inducing cocktail can be easily avoided, however, with minimal self control. Eat your turkey and veggies to your heart's content, just cut back on the refined carbs and simple sugars. This simple action will decrease the carbohydrate load and the total amount of food ingested. Two birds, one stone, you're welcome!