What Causes That Post Meal Crash?

It seems as though nodding off after a holiday meal is just as much of a tradition as eating a Christmas tree or decorating a Thanksgiving turkey.  (Did you catch that or did I catch you drowsy from your last meal?) But why does this happen?  And worse, are you someone who is routinely tired after meals, regardless of the time of year?

The reason behind this varies depending on your specific situation, but mainly involves too many carbohydrates and poor blood sugar control.  Ideally, when we consume carbs/sugars the pancreas releases a proportionate amount of insulin which then delivers the glucose (end result of crab breakdown) to our cells for energy.

On one level we have someone who usually eats relatively healthy, but just consumed a carb load as if they were preparing to hibernate.  The flooding of glucose into the blood alarms the pancreas who, being the diligent little organ he is, dumps insulin to handle the carb load. (Elevated insulin levels due to too many carbs or outright insulin resistance is also not a good thing and has been linked to everything from inflammation to autoimmunity and cancer).

The pancreas wants to make sure all the glucose can catch a ride to a cell so it overcompensates with the amount of insulin secreted.  This also happens with people who have poor blood sugar control (aka dysglycemic).  The end result here is the glucose being cleared from the blood so rapidly that you have now gone from one extreme to the other; from blood sugar spike to crash.  This can lead to symptoms of hypoglycemia; which include light headedness, headaches and feeling tired.

Another reason for the post meal siesta occurs when our tissues become resistant to the insulin that is attempting to clear the blood of and deliver glucose.  This can also happen from over doing it on carbs and is the mechanism behind diabetes type II.  Anyone concerned with intelligently controlling your weight should perk up for this explanation.

When your tissues become insulin resistant due to poor diet, lack of exercise or binge eating, the glucose remains in the circulating blood causing damage to your brain and blood vessels. (We then have our body’s natural bandaid called in (cholesterol), to patch up the damage from the dysglycemia and insulin resistance.)

Your body wants to keep your blood glucose levels under control, so when plan A doesn’t work (glucose cleared from blood by insulin), plan B kicks in.  The glucose is then converted to triglycerides and stored around your midsection as, you guessed it, fat.  In many cases it’s excess carbs, not fat in your diet that leads towards poor blood sugar control, possible diabetes, insulin resistance, aaaaand additional weight gain in the form of glucose being converted to and stored as body fat.

This conversion of glucose to triglycerides en route to your fanny is a process that requires a lot of your body’s energy/fuel.  So much so that it actually leaves you tired and crashing, and thus we have the post meal coma.

Add to this the fact that this process can also raise serotonin levels.  As we’ve discussed in past posts, serotonin is actually the precursor to the sleep hormone melotonin, and because of that can induce drowsiness.  This is also the reason turkey knocks you out as it contains the precursor to serotonin, tryptophan.

Hopefully this sheds some light on the subject for those curious about why we hit the hay after scarfing down a delicious feast.  Enjoy the holiday.  Indulge if you like as you now know what’s going on within and the possible dangers routinely doing so can pose.

However, if you are someone who struggles with cravings, crashes, and weight as we discussed, make it a point to address these signs of internal dysfunction before they get worse.  We’re coming up on a new year which serves as an ideal time to get serious and make your health a priority.

Again, enjoy the holidays and come see us when you’re ready to step it up in the new year.

2 responses to “What Causes That Post Meal Crash?


    • Thank you for the kind words and interest. Feel free to always bring the feedback, as well as suggestions if you have any comments, questions or concerns.

Leave a Reply


WordPress.com Logo


Twitter picture


Facebook photo


Connecting to %s