Yawning, carbs and low-blood-sugar: any connection?

Answered on August 19, 2014
Created May 11, 2012 at 1:02 AM

I regret a series of bad decisions today.

I ended up at TGI Fridays, and got an 8oz steak (butter topped), and 2 servings of sweet potato fries. Before you yell at me for the sides, let me explain that I have multiple areas of my small intestine that are extremely narrowed (from past crohn's scarring). Though I've been in remission for 20 years, and feeling great, I can't eat anything that doesn't fully dissolve into liquid before it reaches that point. That' means no nuts, salad, fiberous fruits or veggies. If at home, I can pressure cook carrots, cauliflower, butternut squash to a mush. When I'm out, it's usually not mushy enough for me to eat safely. If I screw up (and I have 4 times in the last 20 years), I end up in the emergency room with a partial small bowel obstruction. They put an NG tube down my nose, into my stomach and decompress the gut: a very unpleasant 2 day hospital stay.

Anyway, I didn't feel comfortable with with any of the side orders, so I went with the double fries.

Not surprisingly, I became tired after lunch, which was really bad because I had a 2 hour drive in the afternoon. Despite me having 5 squares of 85% dark choc, I was yawning and very tired. I finally resorted to a sugar free Monster Energy drink. All in all, an embarrassing sequence of events which left me feeling like a complete failure.

Now for my question:

What's up with the yawning?

I always thought that yawning was when your body wanted to send more oxygen to your brain? That didn't seem applicable to this situation.

I do know that if you eat a bunch of carbs, your body produces insulin, and sometimes too much, which will cause a blood sugar drop.

Shouldn't my dark chocolate have counteracted that?

And, from a blood sugar perspective, I guess the sugar-free energy drink wouldn't help either because it contained no sugar.

By the time I got home (4 hours after lunch, 2 hours after the last bit of chocolate, and probably about an hour after finishing the last bit of energy drink), I tested my blood sugar. (No, I'm not a diabetic, but my partner is, and I have access to a glucometer.)

My blood sugar was 79. (I don't regularly test, so I don't know if that's too low, or low enough to account for yawning, or even if yawning is related to low blood sugar).

Since I pretty much screwed up my day, I decided to finish up a green smoothie before going VLC tomorrow. I had the smoothie about an hour after dinner (4oz of dark chicken, 1oz butter, 1.5oz of bacon). Again: I was a YAWNING MACHINE! I took another blood sugar reading (about 30 minutes after the smoothie), and it was 111.

Is this yawning at all related to blood sugar?

Is it caused by the carbs (or the insulin response to it)??

What the heck is going on here?

Thanks, Mike

5'10" Male, 188lbs (lost 10 of the 20 I'm trying to) in the last 3 months of going paleo.

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3 Answers

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on October 18, 2012
at 01:59 AM

  • Food causes a spike in blood sugar followed by a decline in blood sugar. I'm pretty sure that blood sugar is expected to be low 4 hours after a meal. In the first 20-60 minutes after you eat, your sugar will spike. In the 1.5-2.5 hour range, your blood sugar should be lower than average (plummet). After that, it should be normal. A food's glycemic index changes the time scale of this reaction.

  • Itis is the symptom of feeling sleepy after a large meal. Generally, the worse the meal is (health wise) the greater the itis. Think of it as the first sign of food quality. Just like alcohol is intoxicating, so too does food affect the mind. You can go sober from alcohol, but you've got to eat.

  • There are two reasons for itis. Firstly, insulin causes uptake of blood sugars until there are lower than normal sugars. Otherwise, how would the body know that it had taken up enough of the sugars? The result is that lull in blood sugar soon after a meal. The second cause of the lull is the energy exertion required to actually digest meals.

  • Yawning can be a sign of itis (sleepiness). Thus it can be psychological (driving is inherently a couch-potato, sleep-inducing activity). Physiologically, yawning acts to improve the exhalation of CO2. CO2 is like the exhaust of an engine; it's the byproduct of burning energy, especially carbohydrate energy. You give off less CO2 when burning fats than when burning sugars. Thus, the exertion of burning sugar energy to digest your meal increased your CO2 enough that you had to yawn it out.

Of note: I'm not an expert, just someone with a science bachelor's degree. Thus, take my words with a grain of salt (but not sugar).

P.S: I'm not paleo.


on March 27, 2014
at 07:42 PM

For a good number of years I used to have fits of yawning most evenings, which would last about half an hour to an hour, and I could not understand why and it used to drive me crazy. One evening, during my yawning fit, I ate something and the yawning stopped. As my husband is Type 2 Diabetic I began to think my blood sugar must me low. I got on the web and began to research hypoglycaemia and found out about the effects of excessive carbohydrates on the body. I bought books about the subject, scoured the internet and eventually found the paleo / primal path. Both my husband and myself have been following this way of life now for around two years and it has made such a difference. His blood sugar is well under control and I only have a yawning fit now if I eat too many carbs with dinner.


on July 10, 2013
at 09:44 PM

Yawning after a meal with carbs is a positive sign of high insulin resistance. The bigger the belly fat, the greater the insulin resistance and the more you yawn.

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