Can I Add Stevia to Keto Coffee? Transcript

stevia in coffee - feature picture (1)

Can I Add Stevia to Keto Coffee? Transcript

Summary | Video | Experiment | Conclusion

Can I add stevia in coffee? Will it break a fast?

We’re back on our testing kick, and we can feel it in our fingers!

In the past, we have tested our blood glucose and ketones to see how different things added to our coffee affect our intermittent fast.

We are now working on testing non-noncaloric sweeteners, and we get a ton of questions about stevia. Stevia is a natural type of sweetener since it is from a leaf.

In this post, we discuss whether it is okay or not okay to add stevia to keto coffee.

Stevia In Coffee Summary

  • Stevia did not have a strong effect on our blood glucose or ketones when looked at alone
  • When compared to black coffee, it’s possible that Stevia blunted ketones (Becky) and raised glucose (Keith), which may indicate an insulin response
  • Adding Stevia to a coffee with fat (i.e coffee with cream, Keto Coffee or Bulletproof Coffee) would have negative consequences if there was an insulin response

Adding Stevia to Keto Coffee…A Bad Idea? [Video]

Stevia is a non-caloric sweetener, but does it impact your glucose or ketones? We tested our blood after consuming coffee with stevia to find out. In this video, we share
1. How stevia impacted our blood glucose and ketone readings
2. How stevia measured up to black coffee alone
3. Our recommendation regarding stevia and keto coffee

Stevia In Coffee: The Experiment


So we got up this morning and pricked our fingers to see what our baseline blood glucose and ketone levels were.

Then we added 3/8ths of a teaspoon of this [Pure Leaf Stevia] into our coffees.

We used 3/8th of a teaspoon because on the package of stevia, it says that 3/8th (.375) tsp. is the equivalent to one tablespoon of sugar. We have tested one tablespoon of sugar in the past and wanted to be able to compare our results from both experiments better.

Stevia In Coffee conversion to One Tablespoon of Sugar

Then we tested our blood again at 30 minutes, 60 minutes, and 120 minutes.

Here are what the results showed:

Becky’s Results


All right, are you ready for this?

So your ketones started at 1.2 mmol/L before drinking coffee.

30 minutes after drinking coffee, it went up to 1.4 mmol/L, then 1.4 mmol/L at 60 minutes, and then back down to 1.2 mmol/L at 120 minutes.

Stevia In Coffee - becky's ketones

So you really didn’t change a whole lot over the two hour period.




Your blood glucose started at 84 mg/dL, went to 89 mg/dL at 30 minutes, then down to 82 mg/dL at 60 minutes, and then finally settled at 85 mg/dL at 120 minutes.

Stevia In Coffee - becky's glucose

So again, a little bit of fluctuation in there, but not a whole lot of movement. It did not do a whole lot.


Yeah, that is kind of arbitrary.


Now, if we compare that to just black coffee without stevia, your ketones in those tests actually went up, and your blood sugar stays about the same.

Chart showing how female's ketones changed from black coffee to stevia in coffee
Chart showing how female's glucose changed from black coffee to stevia in coffee

So that is that question:

Is stevia blunting some of your ketone response?


Right. So when we tested stevia today, if you just look at those results, it’s like, “yeah, it didn’t do anything to me.”

However, if you compare that to not having stevia in my coffee.

Well, black coffee alone increased my ketones, whereas I got no change with stevia added.


It could have negated the effect, but we don’t know for sure. That is kind of conjecture.


Right. Let’s move on.

We have another metabolism going here.

Keith’s Results


So [on the testing day], I was at 0.6 mmol/L for my ketones, which I was super happy about…


Being in ketosis first thing in the morning; It’s not easy for you.


Right, and then I had my stevia, and it knocked me right down to 0.3 mmol/L at 30 minutes.


…and he was not happy.


No, not happy. Then I went to 0.4 mmol/L at 60 minutes, and then back to 0.3 mmol/L at 120 minutes.

Stevia In Coffee - Keiths ketones

So over the two-hour period, it [stevia] completely kept me out of ketosis.

Also, that is only 3/8 of a tablespoon, which is a tiny amount.


Yeah, very tiny.


My blood glucose stayed about the same. I started 94 mg/dL, I went to 99 mg/dL at 30 minutes, then to 89 mg/dL at 60 minutes, and then to 93 mg/dL at 120 minutes.

Stevia In Coffee - Keiths Glucose

So again, it didn’t do a lot to my blood glucose, but if we go back and we look at what happened with black coffee, for me, I had a twenty-nine point decrease in blood glucose when I just had black coffee.

Chart Male subject - how ketones are affected with black coffee vs coffee with stevia
Chart Male subject - how ketones are affected with black coffee vs coffee with stevia

So again, you know, is this just blunting some of these responses? Obviously, I had an insulin response because my ketones went down, and I dropped out of ketosis “officially.”


Yeah, so explain that. So we are looking at insulin…

Stevia In Coffee: Discussion


We are looking at two things.

  1. We are looking at if we have a blood glucose response
  2. We are looking at if we have a ketone response.

That [high-blood glucose] is probably going to trigger insulin. When insulin is high, it shuts off ketosis. When insulin is high, you are storing fat instead of burning fat. So those are the two parameters.

Insulin the fat-storing hormone

If we see both:

  • Glucose Coming Down
  • Ketones Going Up

we know that is a good thing because we know that we are staying in fat-burning mode.

If we see either of those things go the opposite way: Glucose going up or ketones coming down, then we know that we are probably getting an insulin response.

That is going to shut down our fat burning machinery; At least temporarily.

Stevia In Coffee: Conclusion


So, where does that leave us with putting stevia in with bulletproof coffee?

Or a keto coffee where you are mixing fats with the sweetener?


Yeah, I’m going to say it’s bad. Just based on our results.

Of course, I know that we’re going to get a lot of upset comments from people.


So this won’t be a popular video.


I mean, test it yourself and see what works for you. We referred to two different people with different metabolisms and male and female.

For me, I would not use it.

Stevia in coffee - test yourself


Well, and for me, it didn’t taste good, but could it also have blunted my ability to produce ketones? It was pretty inconclusive for me as well.

So there you go. Those are our results that we got with stevia.

Don’t shoot the messenger.


It ruined our coffee too.


All right. I hope that helps give you some insights.

Thanks for watching, and we will be back with some definitive tests on a bunch of different sweeteners for you.

If you would like to see the results of some of our past tests, you can check them out here:

What Breaks a Fast? Our Other Tests

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