The Science Behind Thanksgiving Weight Gain + How to Hack Your Meal

Gobble gobble Maximal Beings!  As Thanksgiving approaches, I thought it beneficial to smash some of the bioscience behind the Thanksgiving Day meal.  Many people will be making delicious food this holiday season and packing on the holiday pounds.  This week at Maximal Being, we discuss the science behind Thanksgiving weight gain and how to hack your meal for success.

Gathered around the table, we share stories, thanks, and food.  Thanksgiving is one of my favorite holidays.  However, this is the time of year that Americans make errors in their eating habits and get off track.  Everyone blames the turkey!  Turkey makes me tired because of tryptophan.  Well, throughout this article, we will make a case in defense of your bird.

How Much Thanksgiving Weight Gain Occurs?

First, let’s prove that people gain weight during this time of year.  Many of you reading this have felt that way, but does this feeling hold in the scientific literature.  Well, in a nutritional review, this study found that 51% of annual weight gain is related to the holiday season, on average 14% of body weight.  That’s right, MOST of the weight gain during the entire year is due to the holidays, and people spend the rest of the year (AKA the gym rush of Jan 2) trying to catch up.

Furthermore, this Thanksgiving weight gain holds across many populations of people. A study of college kids during Thanksgiving showed an average weight gain of 0.5 kg, not a considerable amount.  That said, college kids have youth on their side, and hence, does this apply to you?

For us, metabolic mortals, The New England Journal of Medicine, a top medical journal, evaluated weight gain during the year.  In this group of 195 people, the mean weight gain during the holiday period was higher than the post-holiday period (around 3-4 lbs).  So yes, the average gain of 5 lbs holds for non-college participants as well. 

Does Being Mindful of  Weight Gain Help?

Being mindful of this potential weight gain is essential, but is cutting down on the amount of food enough?  In a study of 31 men and 34 women evaluating dietary intake and restraint.  The obese subjects ate less on average than non-obese.  Men ate more than women.  The degree of control was associated with weight gain and negatively related to dietary intake.

In our metabolically nimble college kids, awareness also does not help the potential for Thanksgiving weight gain.  Does self-awareness impact body composition and weight?  In this study from 2008, the study participants, in this case, college students, did gain weight (about 4-5 lbs). Despite being aware of this weight gain, there was no difference in weight or body composition during this period despite activity changes.  Okay, so awareness and calorie restriction are not enough, but what about exercise.

The Role of Exercise on Thanksgiving Weight Gain

When most of us gather around the holidays, we remain sedentary.  We sit in front of the TV and watch Clark Griswold or the Thanksgiving football game.  What if you walk, run, cycle, lift, or move!  Our article on NEAT discussed how any incremental change in movement could assist with metabolism and hence fat breakdown.  

Furthermore, in our article on EPOC (excess post-exercise oxygen consumption), if you do a high-intensity interval training (HIIT) session, you will continue to burn calories even after your workout for UP TO 48 hours!  Therefore, perhaps HIIT during the holidays is a great way to keep the pounds away.

In this study from Nature, the authors evaluated 48 males and 100 females, tracking anthropometric data around the holiday.  The authors defined exercisers as performing “150 minutes per week of moderate-intensity exercise.”  The ultimate result, the authors concluded that exercise did not protect against weight gain.

Furthermore, in our article on EPOC (excess post-exercise oxygen consumption), if you do a high-intensity interval training (HIIT) session, you will continue to burn calories even after your workout for UP TO 48 hours!  Therefore, perhaps HIIT during the holidays is a great way to keep the pounds away.

In this study from Nature, the authors evaluated 48 males and 100 females, tracking anthropometric data around the holiday.  The authors defined exercisers as performing “150 minutes per week of moderate-intensity exercise.”  The ultimate result, the authors concluded that exercise did not protect against weight gain.

However, despite this linear understanding, the human body is more complex, and the relationship between your foods and your sleepiness is multifactorial.

Blame the Starchy Carbohydrates for Thanksgiving Weight Gain

Most of what you will see are starchy carbohydrates like mashed potato, stuffing if you look at the Thanksgiving table.  The Thanksgiving meal is also very sugary.  Keeping in mind your recommended daily allowance of sugar is 25-50 grams/day, you will likely max out your daily sugar intake fivefold with one meal. 

Don’t get me wrong, I love pie, but carbohydrates will also assist in serotonin absorption.  These starchy or high glycemic foods will also rapidly fluctuate your blood glucose or sugar levels, leading to a subsequent drop in blood sugar.  

Furthermore, having a diet high in carbohydrates was found in this study to increase REM sleep.  Carbohydrates also impact the orexin cells.  Orexin cells are cells in your body that partially control your wakefulness.  So, I would blame the pie and not the turkey.

Blood Flow and Parasympathetic Activation Causing Thanksgiving Fatigue

When you eat, your blood volume, roughly six Liters, concentrates toward the GI tract (postprandial hyperemia) and away from the other portions of your body.  Though you still obviously get blood flow to the brain, the volume is less.  Add on someone with plaques in their arteries flowing to the brain, which will further exacerbate this flow issue, making you sleepy.

Besides, the parasympathetic (rest and digest system) and enteric nervous system kick into gear.  As we discussed in our article on the brain-gut axis, hormones like serotonin are vital to your gut movement and motility.  These nervous systems will release such hormones in response to food, which is sedating.  The downregulation of the wakeful fight or flight sympathetic nervous system, fueled by adrenaline (epinephrine and norepinephrine), is also a factor for those sweet potato casseroles you are eating.

Leave the turkey alone.  Turkey is a fantastic source of protein.  Despite the consumption of turkey this time of year by most, I eat turkey all year round.  It is lean and loaded with a protein/pound ratio few foods can rival (122 grams/lb). 

Also Blame Alcohol for Holiday Weight Gain and Sleepiness!

Another reason why people may gain so much weight around the holidays is alcohol.  In our articles on drink, science, the startling science behind alcohol and drinking, and drinking + maximal being, we go into the impact that alcohol has on your metabolism, sleep, stress, and body.

In general, people drink more alcohol around the holidays, thus adding calories, sugar and allowing you alterations in your hunger signals, so you eat worse food options.  Your sleep is impaired, as we discussed in sleep and alcohol. Therefore, your training performance suffers.  The result is weight gain, as discussed above.

To avoid this chain of events, make better alcohol choices, eat before drinking, or prevent or limit your intake.  Remember, that egg nog is not only a sugar bomb but sticks around for 10-14 days to mess up your goals.  

How to Limit the Thanksgiving Weight Gain

Apart from alcohol avoidance limitations, you can make small and simple changes in your turkey day to limit weight gain.  First, fast.  As we discussed in our article on intermittent fasting, this is a great way to start your day with your metabolic engines firing.  Ensure you get enough water that day by starting with a glass or two of filtered H2O.  After all, near all of your metabolic processes require water.

Move!  Get up and walk, stand while watching your football game.  Better yet, play football with family, friends, or loved ones.  Train, lift, or do a HIIT, and you will enjoy those yams even more!

Finally, watch your starchy carb and sugar intake.  The Thanksgiving table is full of these choices when really for maximal health.  Keep starchy carbs to ¼ of your plate, like mashed potatoes, dressing, or yams.  Make ½ of your plate a non-starchy veggie like brussels sprouts, broccoli (also with anti-oxidants called sulforaphane), greens, and ¼ the bird.  Limit your pie to 1 slice.  Finally, if you are planning for dessert, skip the seconds.

Hopefully, you have learned enough to learn that your turkey is not to blame for Thanksgiving weight gain or sleepiness. Instead, look to the starchy carbs and the metabolic impact of these everyday Thanksgiving staples.  Realize that weight gain during the holiday accounts for most of your overall weight the entire year, and head into your holiday season by making small tweaks that allow you to enjoy your community, meals, and health.