Does Coffee Raise Blood Sugar? Preliminary Findings.
A few weeks ago, I started an experiment to better understand how different foods and lifestyle decisions impact blood sugar, using a constant-glucose-monitoring device.
Right now, I’m testing what effect drinking coffee has on blood-sugar levels.
Here’s the preliminary data:
The blue line is the blood glucose on a day I drank coffee. The red line is on a day without coffee. As you can see, the blood-sugar levels are on average higher when drinking coffee than when not (I added nothing to the coffee).
To reduce the probability that this difference is random, I’ll repeat the experiment this week.
What do you think will happen? On days when drinking coffee will the blood sugar be (on average) higher, lower or the same? Leave your guess in the comments below.
We’ll share our findings in a few days.
Earlier experiments
Are you interested in our earlier tests? Check out the series:
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Is 60 a good blood sugar number or is that low?
But interesting work!
Like a lot of Information that was preached on weight loss we were told that coffee was not a problem, WELL, I joined the Diet Doctor and I am following the LCHF diet I do not cheat I am a T2 Diabetic on Insulin Injections 4 times a day
I have lowered my A1C from 8 to 6 and reduced my Insulin Injections by 2 a day
I get very discouraged when I get a High reading now. So I look back to see what went wrong What did I do to have this Increase and the CULPRIT IS COFFEE
This site has great Information on all aspects of weight loss But I need more information on a T2 trying to reduce Insulin Injections another Culprit in weight control: My weight problem ballooned when I was put on Lantus Long Acting Insulin
My weight problem ballooned when I was put on Lantus Long acting Insulin
Would be interesting to know if there are similar differences between regular and decaf w.r.t. blood glucose levels.
Insulin causes insulin resistance.
I've tried to test this myself, but there are too many variables, not the least of which that the blood sugar monitors have a lot of errors. If coffee has an effect, it's subtle. I've taken my blood sugar in the morning, then had coffee, then taken my blood sugar about an hour afterwards. Sometimes it does up slightly, but most times, it goes down.
What would be interesting to see was if there was an insulin effect. That would also affect blood sugar. Maybe coffee reduces insulin? That would yield a higher blood sugar, but would cause less hunger.
This is one day's data for each case? It would be good to have a bunch of days of data to work with since there can be significant variability in glucose on any given day. And we see that here in blue which is bouncing around all over the place even before you have your coffee. Really, both of them are moving around a fair amount.
I repeated the experiment yesterday and today - will probably share the results this week.
Do you know of a simple and reliable way of measuring insulin levels several times during the day?
I have been to Dr. Fung's Site I find the Information more confusing
He does not give out Individual help to Insulin Problems Which is understandable, He refers you to your Doctor and I have one who is not in agreement with LCHF diets or reversing T2 Diabetes
Like many, We go it alone
These people can help you:
https://www.virtahealth.com/
Best of luck!
Check out https://www.dietdoctor.com/diabetes
What is apparent is that after not eating or drinking for 4 hours your BG drops to 65 as opposed to drinking coffee approx 77. So as mentioned drinking coffee at first sight appears to keep your BG stable but there is not enough information and the reasons why blood sugar levels rise and fall can involve a different pathway each time. The body is always using energy the best way possible.
My guess is that the sudden drop in BG ten minutes after drinking coffee could be caused by adrenaline or perhaps the incretin hormones from the gut are rising which will increase insulin production that results in the momentary drop in BG.
I have also heard that it is well known that coffee assists with fat burning. If this is the case then since Bjarte is keto adapted he may be approaching fasting BG level after 2 hours but by drinking coffee he further stimulates fat burning (lypolysis) which increases the output of Free Fatty Acids and Glucose from the liver as it breaks down the flow of triglycerides coming from the adipose tissue. The increase in glucose production from the liver would explain the BG 77 being above the fasting 65.
However there may be a slight effect on either insulin or Glucagon secretion; thus might decrease or increase blood sugar.
Vjarte Bakke, Did you established the base line of your fasting levels for many days or you just picked a random one day fasting?
Thanks for the post ... very helpful
I ate ketogenic both days and similar foods but not exactly the same. I didn't eat anything 10 hours before the experiment, and nothing during the experiment.
Sleep, stress, and activity levels were all similar both days.
Fair point, the results could be random variability.
I'm in ketosis and therefore less sensitive to lower levels of blood glucose.
(And no, I do not take sugar in my coffee and I only drink sugar-free energy drinks)