Blood Sugar vs. Popcorn – Is Adding Butter Better? 

Blood Sugar vs. Popcorn – Is Adding Butter Better? 

Video | CGM | Plain Popcorn Results | Buttered Popcorn Results | Popcorn Blood Sugar Comparison | Takeaway

A couple of months ago, I used my non-prescription CGM to see how plain popcorn would affect my blood sugar level. The result was very poor. It shot my blood sugar straight up and then just as quickly dropped the level to a point lower than my starting point. 

Sharing that result spurred a lot of questions about buttered popcorn. Since butter is pure fat, which is a nutrient that does not spike blood sugar, would adding butter to the popcorn make it a better snack for blood sugar control? Well, I ran the test. It should be better, right? It was not what I expected. Here are the results. 

Blood Sugar vs. Popcorn – At-A-Glance 

  • Maintaining a stable blood sugar level throughout the day limits the fat-storing hormone insulin, controls hunger, and lowers disease risk.
  • The best snacks for blood sugar control cause a minimal blood sugar spike immediately after eating and a stable or gentle blood sugar rise and fall in the two hours after consumption.
  • Dietary fat (butter) is a macronutrient that causes little or no rise in blood sugar, protein causes a moderate rise, and carbs (popcorn) cause the highest rise. 
  • Plain popcorn is mostly carbohydrate with a low fiber-to-carb ratio and minimal fat, which led to a big blood sugar spike and crash.
  • When calories remained constant, adding butter to popcorn caused a less dramatic blood sugar spike and drop, but the result was still poor.

Blood Sugar vs. Popcorn – Is Adding Butter Better? [Video]

In this video, you’ll learn…

  • The methods and materials I used to test both foods fairly.
  • The effect plain and buttered popcorn had on my blood sugar levels.
  • Why buttered popcorn may not be as good as it seems.

CGM (Continuous Glucose Monitor)

I used a non-prescription CGM from Levels to analyze my blood sugar levels. CGM stands for continuous glucose monitor. It is a device that you attach to your skin, typically your upper arm or belly. It measures the fluids around your cells, called interstitial fluid, to gauge your blood glucose (blood sugar) level. 

Being able to monitor your blood glucose daily without a finger prick makes it easy to watch your daily trends and make adjustments to potentially reduce your risk of developing the disease. If you are interested in using a CGM to monitor your blood sugar, I provided details in my video titled “Blood Sugar vs. Snacks.”

Blood Sugar Results of Plain Popcorn

When I first tested plain popcorn, I ate a 200-calorie portion. I did that because I was doing a side-by-side comparison of popular snacks. 

Plain popcorn did not perform well. It caused an immediate, very steep spike of 150 points, followed by a crash that dropped me 23mg/dL lower than I was before eating it. That was not a favorable response. Levels assigned the plain popcorn snack a 1 out of 10, which is a very poor blood sugar score.

Blood Sugar Results of Plain Popcorn

Why did it perform so poorly? Popcorn is a whole-grain snack, which makes it seem like it should be a high-fiber snack. However, the 200-calorie portion of popcorn contained only 7.5g of fiber and over 40 grams (40.2g) of carbohydrates. So, its fiber-to-carb ratio is not strong, at about a 1 to 5 ratio. Plain popcorn is also a low-fat snack with a modest amount of protein. 

That macronutrient breakdown helps us understand the blood sugar response. We know that carbohydrates, especially low-fiber carbs, cause a quick and steep rise in blood sugar, dietary fat has little or no blood sugar effect, and protein causes a moderate rise.

Because plain popcorn is high in carbohydrates, with a so-so fiber-to-carb ratio, and relatively low amounts of fat and protein, it made sense that it digested quickly and spiked my blood sugar. 

What about Buttered Popcorn? 

After I shared those test results, many people asked, “What would happen if you added butter to the popcorn?” It’s a good question because many people do, and consuming butter, which is pure fat, does not cause a rise in blood sugar.

So, I ran the test.

Blood Sugar Results of Buttered Popcorn

A 200-calorie serving of plain popcorn was 6 ½ cups (52g). I wanted to keep 200 calories as my standard for comparison, so I cut the volume of popcorn in half and added one tablespoon of melted butter. 

This was not a formal lab study, but I kept as many variables as possible consistent on testing days. Specifically, I ate the snacks at 7 a.m. after an overnight fast. I did drink black coffee, but I did not exercise during the 2-hour testing period. 

When two hours passed, I was surprised to see that the buttered popcorn snack received a score of 1 out of 10, the same very poor score as plain popcorn. It did not cause as dramatic a spike as plain popcorn, but it did cause a spike followed by a drop below my starting point. 

Blood Sugar Results of Buttered Popcorn

 To all of you popcorn lovers out there. I’m sorry it had to be that way.  

I thought that cutting the carbs in half and replacing them with fat would cause much more blood sugar stability than it did. The buttered popcorn response was not as pronounced as the response to plain popcorn. However, it was not great, and I will discuss the problems in a moment. But first, let’s focus on blood sugar.

Comparison: Is Buttered Popcorn Better than Plain?

When calories are held constant, is buttered popcorn better for blood sugar than plain? You can argue that, yes, it is. If that is the only goal, then cutting the carbohydrate (popcorn) in half and adding fat (butter) will create less of an initial blood sugar response. 

Comparison: Is Buttered Popcorn Better than Plain?

Plain popcorn shot my blood sugar up by 150 mg/dL. The rise after eating buttered popcorn was just under half of that, causing a 70-point rise

However, your immediate blood sugar response to a single food is not the only determining factor for healthy snacking. If you have a bigger goal, like weight loss or long-term blood sugar regulation, adding butter to your popcorn will not improve much. 

The Problems with Buttered Popcorn

Here are the challenges with buttered popcorn. 

Problem #1

First, it tastes better, and usually, we also add salt. That gives us a snack with the proven addictive combination of sugar, fat, and salt. That combo sets off appetite alarm bells throughout your body, which I can attest to. 

I ate 200 calories of buttered popcorn for breakfast and could have easily eaten another serving or more. That would have been fun in the moment but given me many more calories than my body needed, creating an uphill battle when it comes to weight control. 

Problem #2

Second, quick-digesting carbs plus fat is a good recipe for fat storage. Carbs are easy energy that quickly moves from your digestive tract to your bloodstream. That quick dose of sugar tells the pancreas to release insulin so those high-energy sugar molecules get moved into your cells asap. Dietary fat is slow to digest, breaking down and trickling energy into your blood over time.  

This combo of quick and slow-digesting energy is fine if you do something physically taxing. However, when do you typically eat popcorn? If you are eating buttered popcorn on the couch as you watch a movie, your body does not need all of that energy. 

When calories are considered, buttering popcorn will blunt the initial insulin spike. But insulin is still secreted to move the sugar from the snack out of your blood. If you have no immediate need for energy and the limited glucose storage units (glycogen) are full, the excess gets converted to fat.

And that’s not the end of the story. Digestion is not over. By the time those quick-burning carbs are absorbed, the dietary fat from the butter is making its way into the bloodstream. That energy is not immediately needed, so it gets stored as body fat. 

Problem #3

Even if we go beyond weight loss, combining quick-digesting carbohydrates and fat, as we see with popcorn and butter, is not a long-term strategy for better health. 

What happens in the 2 hours after eating is valuable to know. However, better health comes from what happens over days and weeks. You want to see a stable blood sugar level where you spend most of your day between 70 and 130 mg/dL. If your blood sugar stays high or bounces up and down at a higher-than-normal level, it may indicate that insulin is having a tough time doing its job. 


What we see from this test is that plain popcorn does not contain enough fiber, fat, and protein to slow the digestion of the carbohydrates it has. For me, this caused a rapid blood sugar rise and fall. Cutting the carbohydrates in half and adding fat slowed digestion and blunted the blood sugar response but did not negate the rise and fall.

The bottom line is this. If minimizing blood sugar spikes is your top priority, adding butter or another fat, like olive oil, to your popcorn is better. However, if you have an additional goal, such as weight loss or improving long-term blood sugar regulation, you are not doing yourself any favors by adding butter. 

bottom line

And two closing thoughts. 

First, these are my results. Blood sugar levels depend greatly on your metabolic health, which is unique to everyone. The results I get will not be the same for everyone. 

Also, as we see from this popcorn test, combining foods changes how your body handles them. That is why it is valuable to monitor your blood sugar level. 

Thank you for reading and have a wonderful week!

Additional Blood Sugar Tests

How Did Dark Chocolate Affect My Blood Sugar?

Blood Sugar vs. Snacks [Chocolate, Popcorn, Almonds, Hard-boiled Eggs]

About the Author

Becky Gillaspy, DC, is the author of The Intermittent Fasting Guide and Cookbook. She graduated Summa Cum Laude with research honors from Palmer College of Chiropractic in 1991. 

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