I’m tied up all weekend with work, so no time to post. Tons of interesting experiments coming up, though:
Flour replacements: Just finished up testing of the last flour, so just need to test how much water each absorbs and write up. Very interesting results, some surprisingly good, some surprisingly bad.
Allergy study: got great feedback on my proposed protocol, ready to finalize & pre-register and get going on the tests.
BP & breathing: got great feedback on my proposed protocol, ready to finalize & pre-register and get going on the tests. I also have preliminary data from exploring different breathing protocols to hone in on the most impactful before starting.
Commute studies: Got curious about how to speed up my commute and have been tracking time using different routes.
If I have time, I’ll post a little during the week so as not to build up a backlog, but at worst will resume next Saturday.
Acknowledgements: Thanks /u/genetastic for advice on the statistical analysis!
This post is an update on my experiments to quantify the effect of vinegar on blood glucose & to better understand the underlying mechanism by determining how this effect varies with person/metabolic status, dose, source of calories, and type of acid.
In Phase 1, /u/genetastic, /u/kabong, and I replicated the literature showing that vinegar can reduce the blood sugar impact of complex carbohydrates (white bread). From those experiments, we found that:
Vinegar significantly lowered blood glucose
Peak change in blood glucose & iAuC were reduced by 20% and time to peak blood glucose & initial rise were slowed by 15-20 min. (30-50%).
P-values were all <0.05, with the exception of the drop in iAuC, which was 0.12
The concentration of vinegar we used was extremely unpleasant to consume. So much so that I, at least, wouldn’t be willing to use it for additional experiments, much less daily life.
In this Phase, I tested a more palatable protocol, vinegar diluted in water (~30g vinegar in ~325g water) drank immediately before the meal. Here’s a summary of the results & next steps (full details below):
Diluted vinegar had a statistically significant and meaningful impact on blood glucose compared with no vinagar:
Peak change in blood glucose and iAuC were reduced by ~20% and time to peak was slowed by ~20 min.
P-value was <0.05 for the change in peak blood glucose, but not for iAuC and time to peak.
Diluted vinegar gave very similar results to undiluted, with virtually no change in peak blood glucose and only a modest increase in iAuC and decrease in time to peak. None of these differences were statistically significant.
These results give further evidence that the effect of vinegar on blood glucose is real and provide a practical protocol that can be used for further experiments. For the next phase, I will be testing the following:
Alternate macronutrients (simple sugars, proteins) to determine scope of the effect
Alternate acid sources to test the amylase-inhibition hypothesis
Whether this effect is significant with full meals, including insulin doses
For this last experiment, I will randomly drink 30g ACV in 325g water before my standard breakfast (50g ketochow, 2 tbsp butter, water to 12 oz total volume) and monitor BG impact.
It would significantly improve the study to have a larger number of participants. If you’re interested in collaborating on this or other scientifically rigorous self-experiments with low-carb foods, supplements, or other health interventions, please let me know in the comments or via the contact form on the right.
I’m always looking for collaborators for future experiments. If you’re interested in collaborating on scientifically rigorous self-experiments with low-carb foods, supplements, or other health interventions, please let me know in the comments or via the contact form on the right.
I posted initial results from testing of flour replacements this week. Of the 7 flours I’ve tested so far, all have been pretty good, with peak ∆BG of 16-29% of wheat flour by weight and 9-23% by volume (see post for details).
The post got a huge response, the most site visits and first-day comments on Reddit of any post so far. I’ve definitely hit on something people are interested in. From the comments, I also got tons of new flour replacements to try, almost double what I had found on my own.
Experiments this week focused on flour replacements and vinegar experiments. Next week will focus on continuing both of these, as well as figuring out protocols for some non-food studies I’d like to get going around breathing, blood pressure, and palm-cooling.
– QD
Active & Planned Experiments
Blood Glucose Impact of Low-Carb Foods & Ingredients
Goal: Determine blood glucose impact of low-carb foods and ingredients
This post is an update on my experiments measuring the effect of low-carb foods and dietary supplements on blood sugar.
I’m still working my way through low-carb flour replacements, but since I’m running the vinegar experiment in parallel, it’s going to take a while to get through all of them.
In the meantime, I wanted to share my preliminary results and see if anyone has suggestions for additional low-carb flours to add to the study.
If you have any low-carb flour replacements you like or would like to see tested, please post it in the comments or send me a PM (contact form on the right).
Next week I’ll have an update on the vinegar experiments.
Historically, there hasn’t been a lot of low-carb replacements for flour available, mostly almond flour, coconut flour, and resistant starches. Similar to other low-carb products, a ton of new flour replacements have hit the market in the last few years. As always, the net carb counts look good, but I wanted to test them to see if they really hold up (see evidence of blood glucose impact of dietary fibers here & here).
So far, I’ve found 11 flours to test:
Baseline:
Wheat flour
Modified starches
Carbalose flour
Carbquick
Freekeh flour
Nuts:
Almond flour
Hazelnut flour
Beans:
Lupin flour
Okara flour (from soybeans)
Other seeds:
Coconut flour
Hemp protein powder
Flaxseed meal
Psyllium husk powder
I’ve gotten through 7 so far and all have been pretty good, with peak ∆BG of 16-29% of wheat flour by weight and 9-23% by volume (see chart below).
As mentioned above, since I’m running the vinegar experiment in parallel, it’s going to take a while to get through the remaining flours. Once I do, I’ll post a full update with more detail on taste, texture, and the full blood glucose analysis.
If you have any low-carb flour replacements you like or would like to see tested, please post it in the comments or send me a PM (contact form on the right).
I’ll test all the requests over the next couple weeks and post the results.
My testing of low-carb breads was just published on Diabetes Daily. If you got here from that article, here’s a few other studies you might be interested in:
I also post self-experiments on other topics, including sleep, exercise, and other health interventions.
I’m always looking for collaborators for future experiments. If you’re interested in collaborating on scientifically rigorous self-experiments with low-carb foods, supplements, or other health interventions, please let me know in the comments or via the contact form on the right.
