Reader Requests: Blood Glucose Testing of Tortillas, Ice Creams, Breads, and Yogurt

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This week in my low-carb food study, I have Reader Requests!

For the past 6 weeks, I’ve been posting a series of studies on the blood glucose impact of low-carb foods (tortillas, cereal, ice-cream, bread). In the comments for each of these posts, I’ve been getting some great recommendations for other foods to try, so I decided to do a “Reader Requests” study where I measured the BG impact of the recommended foods.

The results were really interesting. In every category, there was a Reader Request that either had a much lower BG impact than what I had found or gave significant insight into the BG impact of different ingredients.

Here’s what I found:


Summary

  • Tortillas
    • The regular flour tortillas were much lower impact than I expected (30% peak BG & 70% iAuC vs. glucose), similar to that of the resistant wheat starch tortillas. This makes the resistant starch tortillas look even worse than I originally thought. Definitely never going to eat those again.
    • Neither of the recommended low-carb tortillas (Mr. Tortilla & A La Madre) beat out La Tortilla Factory for taste, texture, and BG impact, so I’m going to stick with La Tortilla Factory for personal meals.
  • Ice Cream
    • All three of the requested low-carb brands had lower BG impact than any of the brands I’d previously tested. The Two Spoons brand, in particular, was extremely good and has the only fruit-flavored low-carb ice cream I’ve seen. The Two Spoons Strawberry and Brownie Fudge flavors are my new favorite by a pretty wide margin.
  • Breads
    • The Julian Bakery breads were very low carb, but didn’t taste much like regular bread. They were interesting, but if I’m looking for a bread replacement, I’d pick something else.
  • Yogurt
    • Two Good Strawberry Yogurt had good texture and low BG impact, but the flavor was too mild and had a stevia aftertaste I didn’t like.
    • I would prefer to eat their plain yogurt and add my own mix-ins, maybe some nuts or chopped chocolate for a dessert.

Note: Readers also recommended several of the best breads that were included in the original bread post, including: Carb0naut (Can’t find the original request, sorry), Unbun Unbread (u/fawkesandholly, u/Impressive_Citron_84), Kiss My Keto (u/justjules83), and Base Culture (u/Spell_Chick).


If there’s anything else you want to see me test, please let me know in the comments.


– QD


Details

Tortillas

Tortillas tested. New requests in orange.
Blood glucose impact of tortillas.

Summary: Nothing spectacular here, but the Mr. Tortilla could be good if you prefer smaller size tortillas/soft tacos.

  • La Tortilla Factory Flour Tortilla (not low-carb, as a control) (Can’t find the original request, sorry)
    • Much lower impact than I expected (30% peak BG & 70% iAuC vs. glucose), similar to that of the resistant wheat starch tortillas. This makes the resistant starch tortillas look even worse than I originally thought. Definitely never going to eat those again.
  • A La Madre Low-Carb Corn Tortillas (Requested by u/ADifferentJason)
    • About the same BG impact as the regular flour tortillas (23% peak BG & 63% iAuC vs. glucose). Not great and not consistent with the claimed net carbs.
    • Taste was only ok, too. Will not use again.
  • Mr. Tortilla 1 Net Carb Tortilla (Can’t find the original request, sorry)
    • About the same BG impact as the best-in-class La Tortilla Factory tortillas (14% peak BG & 40% iAuC vs. glucose, or about half the LTF flour tortillas)
    • I didn’t like the taste as much as the LTF low-carb tortillas (bit too gritty), but they’re taco sized, which is very convenient for some recipes.
    • All-in-all, I found these to be ok, but will continue to buying the La Tortilla Factory low-carb tortillas going forward

Ice Cream

Ice cream tested. New requests in orange.
Blood glucose impact of ice cream per gram.
Blood glucose impact of ice cream per gram, zoomed in to only show low-carb ice creams.
Blood glucose impact of ice cream per cup, zoomed in to only show low-carb ice creams.

Summary: All three of the requested low-carb brands had lower BG impact than any of the brands I’d previously tested. The Two Spoons brand, in particular, was extremely good and has the only fruit-flavored low-carb ice cream I’ve seen. The Two Spoons Strawberry and Brownie Fudge flavors are my new favorite by a pretty wide margin.

  • Talenti Double Dark Chocolate (not low-carb, as a control) (Can’t find the original request, sorry)
    • BG impact was consistent with the carb count (peak BG 27% of glucose, total carbs 31% of mass), and way higher than any of the keto brands. Not surprising.
  • So Delicious Chocolate (u/alltheketoladies)
    • Lower BG impact than any of the original brands I tested (2.0% peak BG & 5.5% iAuC vs. glucose)
    • Much harder texture out of the freezer than heavy cream-based ice cream. Even after sitting out for 35 min., I had to microwave it to get to my desired softness.
    • Had a strong chocolate and coconut taste. A lot lighter/airy than the heavy cream based brands, but still had a “creamy” texture.
    • Overall, I didn’t like it as much as the other brands, but I could see some people preferring it.
  • Nick’s Coffee Karamell (u/milliondollarman2019, u/WakeOfTheFlood)
    • Lower BG impact than any of the original brands I tested (2.5% peak BG & 5.9% iAuC vs. glucose)
    • Softest texture of any of the brands. This and Two Spoons were the only keto ice creams that could be “scooped” straight from the freezer.
    • The Coffee Karamell flavor is more mild than I’d like, but it’s ok. I’d really like to try some of their other flavors, but this is the only one in my grocery that’s low-carb.
    • Way lower calories than other brands (240 kcal/pint vs. 470-680 kcal for other brands). Not sure why, though maybe it’s got a higher water content with more stabilizers & emulsifiers to soften.
    • Warning: The nutrition label on their website doesn’t match with what I found in the store. The BG impact matches up with the label, so if you’re buying this, make sure you read the label carefully.
  • Two Spoons Chocolate & Strawberry (u/Harleydemondog)
    • The lowest BG impact of any ice cream I’ve tested:
      • Chocolate: 1.8% peak BG & 4.2% iAuC vs. glucose
      • Strawberry: 2.0% peak BG & 4.9% iAuC vs. glucose
    • This has the most similar texture to regular ice cream of all the brands I’ve tried. Scoopable, but a bit hard straight from the freezer. 1 min. in the microwave at 30% power got it to my preferred texture.
    • The chocolate flavor was good, though I’d prefer a stronger flavor.
    • The strawberry was amazing. Extremely smooth, creamy taste and the strawberry mix-ins taste like firm strawberry jam. This is the only keto fruit flavored ice cream I’ve found. I’ve always preferred fruit-flavored ice-creams and this was a great example.
    • I also tried their Brownie Fudge & Coffee Toffee flavors, but didn’t do a BG test
      • Brownie fudge: My second favorite after strawberry. A stronger chocolate flavor than chocolate and the brownies gave a nice flavor and textural contrast (even stronger chocolate flavor & soft chewy texture).
      • Coffee Toffee: Very strong coffee flavor with a great texture contrast from chocolate chips and toffee. If you like coffee ice cream, I’d definitely recommend it.

Breads

Bread tested. New requests in orange.
Blood glucose impact of bread.

Summary: The Julian Bakery breads were very low carb, but didn’t taste much like regular bread. They were interesting, but if I’m looking for a bread replacement, I’d pick something else.

  • Julian Bakery KetoThin Bread (Can’t find the original request, sorry)
    • The lowest BG impact of any of the breads I’ve tested (3% peak BG & 8% iAuC vs. glucose)
    • This one was a bit odd. It was soft, moist, and tasted pretty good, but not at all like bread. You can really taste the cream cheese in it.
    • When toasted or fried, it became slightly crispy and the cream cheese taste was much less noticeable.
  • Julian Bakery PaleoThin Sandwich Bread (Can’t find the original request, sorry)
    • 3rd lowest BG impact, after Julian Bakery KetoThin & UnBun UnBread (6% peak BG & 10% iAuC vs. glucose)
    • The bread was a little wet when I opened it and tasted slightly sour. Taste was not that great, though maybe it was starting to spoil? I ate it right after opening the sealed package and 3 days after it arrived, so if it was spoiled, that’s not a good sign.

Yogurt

Blood glucose impact of Two Good Strawberry Yogurt.
  • Two Good Strawberry (u/ploddingdiplodocus)
    • Low BG impact (4% peak BG & 7% iAuC vs. glucose), a little higher than its net carb count (2% of mass)
    • Strawberry flavor is very mild and has a stevia aftertaste that I don’t like.
    • Texture is great, creamy and not chalky like some greek yogurts
    • I didn’t like this and would prefer to eat their plain yogurt and add my own mix-ins, maybe some nuts or chopped chocolate for a dessert.

Design/Methods

Foods. Full nutrient and ingredient info here. Key nutrition facts in the tables in above.

Procedure. At 5:00a, I took 4.5u of Novolog (fast acting insulin, duration of 2-4h), then drank a Ketochow shake (websiteBG testing) at 5:30a. After that, no food or calorie-containing drinks were consumed and no exercise was performed. Non-calorie-containing drinks were consumed as desired (water or caffeine-free tea). At 10:30am-12 pm, the substance to be tested was eaten as rapidly as comfortable and notes on taste and texture were recorded (before observing any change in blood sugar).

Blood sugar was monitored for 5h using a Dexcom G6. Calibration was performed 15-30 min. before the start of each experiment.

Separately, all breads were toasted using a Brava oven (wheat toast, setting 7). Taste and texture were recorded.

Data Processing & Visualization. iAUC was calculated using the trapezoid method (see data spreadsheet for details). Data was visualized using Tableau.

Medication. During these experiments, I took long-acting basal insulin each evening at 9pm (Lantus, 1.5u) and 2000 mg of metformin and multivitamin each morning at 5am. I did not dose for the experimental food ingested.


Data


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Low-Carb Bread: Blood Glucose Testing of 16 Varieties with a few Promising Results

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Photo collage of breads tested

This post is an update on my experiments measuring the effect of low-carb foods and dietary supplements on blood sugar.

This week, I have the results from low-carb breads. Next week I’ll be posting results from commenter requests, followed by chocolate.


Testing Queue:

  • Prepared foods:
    • Snack bars: in queue
    • Chocolate: in queue
  • Ingredients:
    • Flour replacements: in queue
    • Seeds & nuts: in queue
    • Vegetables: in queue
  • Supplements:

Bread

Summary

One of the most difficult foods to make low carb is bread. Flour imparts multiple functions to the final product: taste, texture, water absorption, cohesion (via gluten), browning, food for yeast, etc. There are numerous good substitutes for one or the other of these properties, but to get them all, you’d need a complex combination of ingredients.

Recently, there’s been an explosion of commercially available low carb products both on-line and at supermarkets, including a number of low carb breads. Although the net carb counts look good for most of these, I’ve become very suspicious of the blood sugar impact of some of the dietary fibers used (see evidence of blood glucose impact of dietary fibers here & here). 

To see if any of these low-carb breads would hold up, I tested them myself. I tested 14 breads from 4 different categories (resistant starch, protein & flour or fiber, and egg & nut), plus regular white bread as a control.

This was the most interesting of my prepared food studies so far. There was a huge variation in taste, texture, and BG impact and some mysteries that I’ll need to unravel (what’s going on with the resistant starches?).

Here’s my overall conclusions:

  • Lowest BG impact: UnBun UnBread
    • <10% BG impact of regular white bread; <50% of the next best
  • Best combination of taste & impact: Carb0naut White & Kiss My Keto Golden Wheat
    • ~25% BG impact of regular white bread
    • Very different taste & texture, but both really good
  • There’s a large range in impact from different resistant starches.
    • No idea what’s going on here, but I’m very curious. Maybe I should source/test different resistant starches and see how their BG impact varies.
    • Does anyone have any hypotheses? If so, please let me know in the comments.
  • BG impact is not easy to predict from the primary ingredients or nutrition label due to not knowing the ingredient ratios. Breads with actual flour can have the same impact as ones with indigestible fibers and two breads with the same total and/or net carb count can have wildly different impact.
    • The only way for me to know the impact of a food is to do a controlled test.
    • For someone without diabetes, this would probably require eating a large amount, as you’d need to induce an BG rise (since an insulin spike wouldn’t be measurable).

Does anyone know any other good low-carb breads or other low-carb foods I should try?

As always, please let me know if you have any thoughts, suggestions, or anything else you’d like to see me test.


– QD


Details

Continue reading “Low-Carb Bread: Blood Glucose Testing of 16 Varieties with a few Promising Results”

Request for Requests: What do you want to see me test?

I was hoping to post the results from my bread testing today, but due to a bunch of shipping delays, the last 3 breads didn’t come in time (last one arrives Tuesday). I want to report out a thorough data set, so I’m delaying the report one more week.

In the meantime, I’ve been getting some really great recommendations for low-carb foods and ingredients to try from my previous posts (tortillas, cereal, ice-cream) and on Reddit. I’ve been testing a few and some seem really promising. The top recommendations, Mr. Tortilla tortillas and Nick’s Ice Cream* have been the lowest BG impact in their categories.

Based on this, I’m going to do a “Commenter requests” study where I measure the BG impact of foods & ingredients requested in the comments or by PM.

Here’s what I have so far:

  • Tortillas
    • Mr. Tortilla 1 net carb tortillas
    • A La Madre Low Carb Corn Tortillas
    • Regular (not low carb) flour tortilla for comparison
  • Ice Cream
    • So Delicious No Sugar Added Coconut Milk Ice Cream
    • Nick’s Swedish Style Lite Ice Cream
    • Regular (not low carb) ice cream for comparison
  • Breads
    • Chompies Bread
    • Carb0naut
    • Unbun UnBread
    • Julian Bakery bread
  • Chocolate
    • Lily’s
    • Choc Zero

If you have any low-carb foods, ingredients, or anything else you’d 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.


– QD

* Be careful on the Nick’s ice cream. The nutrition info on the website doesn’t match what I and others found in the store. I’m not sure if they have multiple version under the same name, but I’d carefully check the nutrition info on the physical container. That said, the blood sugar impact I measured matched that reported on the physical container and was the lowest of any ice cream I’ve tested. It was also soft & scoopable straight out of the freezer.


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Effect of Dietary Supplements & Low Carb Foods: Ketochow, Butter, & MSG

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This post is an update on my experiments measuring the effect of dietary supplements and low-carb foods on blood sugar. This is going to be an on-going exploration. Rather than wait for complete sets of data (which would take a long time), I’m going to post each weeks worth of data as I collect it in the hopes of soliciting feedback to guide later experiments.

As always, if you have any comments, suggestions, ideas for new experiments, or want to participate, please let me know in the comments or send a PM via the contact form or to quantifieddiabetes_at_gmail.com.

Planned Experiments

  • Baseline:
    • Glucose re-test
    • Fasting re-test
  • Low-carb foods:
    • Ketochow: This post
    • Carbquick
    • Eggs
  • Supplements:
    • Vinegar
    • MSG: Started 10/2

Preliminary Results: Ketochow, Butter, & MSG

Figure 1.  Change in blood glucose vs. time for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).
Figure 2.  Peak blood glucose for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).
Figure 3.  iAuC for Ketochow by itself (blue) and with 28g butter (orange), 73g butter (light blue), and 28g butter + 10g MSG (red).

Ingredient Background

Ketochow is a low-carb meal-replacement that is designed to have all the macro- and micro-nutrients you need to stay healthy. I have it for breakfast and lunch most days. It’s extremely convenient and surprisingly good. I prepare 16 meals at a time and keep them in the fridge. When it’s time for a meal, I just add hot water, mix, and wait for my insulin to kick in; about 1 min. total prep. time (all-in). It also comes in 18 different flavors, so I can rotate through the ones I like and not get bored. I’ve been using Ketochow for years, so I’ve got my insulin dose pretty well tuned for it. However, following a Reddit post by Chris Bair, the owner of Ketochow on its Glycemic Index, I decided to do a detailed test of its impact on my blood sugar.

Butter is a solid fat source. I use it with my ketochow meals as it doesn’t mix with the powder until melted, giving the mixture excellent shelf-life.

Monosodium glutamate (MSG), is the sodium salt of glutamic acid (an amino acid). It’s primarily used in cooking as a umami flavor enhancer. It’s also been reported to reduce blood glucose when ingested along with a meal (references here). Most of the reported studies were done with high carbohydrate meals and on non-diabetics, so I was interested to test its effect with low carbohydrate meals for myself.


Procedure

I consumed 1.1 servings of the chocolate ketochow (54g, my normal amount) and the specified quantities of butter and MSG mixed with hot water to a total volume of ~12 oz. I then monitored my blood sugar every 30 min for ~270 min. 


Results

As shown in Figure 1, plain Ketochow shows a slow rise of ~40 mg/dL over ~2h. As discussed previously, this is similar to whey protein (the primary caloric ingredient in Ketochow is an 80:20 mix of casein & whey protein) and pretty much what you’d expect from the nutrition label and the amount of insulin I use to cover the meal.

Much more interesting is the impact of butter and MSG. The addition of butter significantly slowed the rise in blood glucose and gave an ~25% reduction in peak blood glucose and 30% reduction in iAuC. Interestingly, increasing the amount of butter from 28 to 73g did not increase the effect, though that was only a single experiment and I need to repeat it to confirm.

For MSG, in contrast to the reported literature, it significantly increased the rate of rise, peak, and iAuC of my blood glucose. This was a single experiment and I haven’t yet done the proper controls (e.g. MSG by itself), but the magnitude of the effect was much larger than I would expect from the amount of amino acid consumed, suggesting it is real. Going forward, I’m going to test MSG by itself, smaller quantities, and also combined with glucose instead of protein fat (more similar to the literature. 


Interim Thoughts and Next Steps

From this preliminary data, it looks like there are meaningful effects of combining macronutrients as well as supplements. Given that, I’m going to stick with this line of experiments. I also like this approach of posting interim data as I collect it, then writing up a more detailed report & analysis once there’s enough data to merit it.

As always, please let me know if you have any thoughts or suggestions.


– QD


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My Next Studies: Effects of Dietary Supplements & Low-carb Foods

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I’ve got my medication re-tuned and my blood sugar is much more stable, so I can start doing more interesting experiments.

Measuring the effect of different macronutrients and low-carb ingredients was really informative. In particular, I’m both fascinated and very disturbed at the huge variation in blood glucose impact of fibers that are listed identically on nutrition labels.

I’d like to continue these kind of experiments, but they were very time consuming and the frequent extended fasts were disruptive to my normal routine. To get around that, I’m going to focus on foods & supplements where I’m looking for relatively binary outcomes (i.e. large effects) and therefore can accept the larger uncertainty associated with not fasting and lower numbers of replicates.

With all that, my plan is to test the effects of popular dietary supplements and low-carb foods to see if claims about them really hold up. To avoid wasting a lot of time chasing after BS fads, I’m going to focus on supplements & foods that are either reasonably supported in the academic literature or otherwise appear to have solid data backing them up. 

Lastly, it’s widely believed that the relative blood sugar impact of foods varies from person-to-person. If you’re interested in helping me to quantify that, let me know in the comments or send a via the contact form or to quantifieddiabetes_at_gmail.com. 

Planned Experiments:

  • Baseline:
    • Glucose re-test:
    • Fasting re-test
  • Low-carb foods:
    • Ketochow: Started 9/26
    • Carbquick
    • Eggs
  • Supplements:
    • Vinegar
    • MSG

If you have any suggestions for supplements or foods to add, please let me know in the comments or send a PM via the contact form or to quantifieddiabetes_at_gmail.com.

Preliminary Results: Ketochow

I don’t want to go a week without posting any data, so here’s some preliminary results from my Ketochow experiments.

Figure 1.  Change in blood glucose vs. time for glucose (blue), whey protein (orange), and Ketochow (brown).

Ketochow is a low-carb meal-replacement that is designed to have all the macro- and micro-nutrients you need to stay healthy. I have it for breakfast and lunch most days. It’s extremely convenient and surprisingly good. I prepare 16 meals at a time and keep them in the fridge. When it’s time for a meal, I just add hot water, mix, and wait for my insulin to kick in; about 1 min. total prep. time (all-in). It also comes in 18 different flavors, so I can rotate through the ones I like and not get bored. 

I’ve been using Ketochow for years, so I’ve got my insulin dose pretty well tuned for it. However, I’ve never actually measured  it’s BG impact directly. A couple days ago, Chris Bair, the owner of Ketochow posted to Reddit about the Glycemic Index for Ketochow. You can’t do a standard glycemic index test, though, as that requires measuring the impact of an amount containing 50g of digestible carbohydrate. For Salted Caramel, that would 62 servings or 2.75 kilograms of Ketochow, which would be impossible to eat.

That said, while the blood sugar rise from carbs should be near zero, the protein should have a small effect due to gluconeogenesis. Since have Ketochow twice a day, I figured I should test it. Towards that end, I consumed 1.1 servings of the chocolate ketochow (54g, my normal amount) mixed with hot water to a total volume of ~12 oz. I then monitored my blood sugar every 15 min for ~270 min.

I’m going to run additional tests with other flavors and with fat sources added, but you can see the preliminary results in Figure 1. The Ketochow was comparable to a similar mass of whey protein, but with a slightly faster rise. This is consistent with the bulk of the macros coming from protein and dietary fiber. 

All-in-all, pretty much what you’d expect from the nutrition label and the fact that I need such a small amount of insulin to cover the meal. Someone without diabetes would almost certainly not be able to observe and blood sugar impact at all.


– QD


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