Blood sugar monitoring


Given the controversy over the maltodextrin in Soylent, I would like to get some hard data on Soylent’s effect on blood sugar.

I have access to a consumer grade blood sugar monitoring device. This weekend, I plan on monitoring my blood sugar after drinking Soylent.

I know that my results cannot be generalized to the population but I want some hard data. I want to know what Soylent does to my blood sugar when I drink it.

I plan on measuring my blood sugar in the morning, after fasting all night. The WHO testing guidelines monitor blood sugar before consumption, and then at 15, 30, 45, 60, 90, and 120 minutes after the start of consumption.

I have dextrose, which I use in a sports drink mix I make for long rides. I can use it one morning to make a reference point with which to compare the Soylent response, which I’ll measure on a different morning.

I would like some guidance from the group as to how much dextrose and Soylent I should consume for each test. The WHO guidelines state ‘50g of available carbohydrates’.

Does that mean I need to consume 50 grams of dextrose to make the reference graph? 50 grams of dextrose is almost enough to make a full gallon of my sports mix, of which I’d only consume a fraction of on a whole day’s ride.

What is a comparable amount of Soylent?

Any advice is most welcome.

Another new research study released about the poor effects of Carbohydrates
Effects of Soylent on Diabetics

I’m very interested in this experiment. You’ve already mentioned (here or in another thread) that you should be able to compare dextrose, 1.0, and 1.1, though I would also be curious about comparisons with pure maltodextrin or a maltodextrin/oat mix in the same ratio as you’d find in Soylent but without the fats and other ingredients (maybe just Soylent without the oil?). I know those might be a little harder to do (and it would take a long time to get yourself to fasting levels, then test each one for two hours without eating anything else), but it would be nice to see.

As for quantity of carbs, if your dextrose doesn’t have anything else in it, then the entirety of it should be available carbohydrates and you would need 50g. If you look at the 10lb nutrition label for one brand of dextrose, it says there’s 18g of carbs per 20g of dextrose, which I think would imply 10% impurities (seems a little high to me). If your dextrose is the same, you might want to consider taking ~55g instead. As another example, this dextrose is 45g of carbs per 46g of powder, so you’d probably want 51g for your experiment.

I’m a little surprised to hear that on a whole ride, you would consume only a fraction of 50g of dextrose. If we use the standard 4 kcal/g for carbohydrates, 50g of dextrose is only 200 calories: not more than a snack’s worth. For this experiment, you don’t have to dilute it down as much as you usually do; I imagine 50g would dissolve nicely in a regular glass of water. You may want to consider using the same amount of water for each trial, or scaling the amount of water with the amount of powder, because that could affect digestion rate. Not sure if your WHO guidelines say anything about that.

50g of available carbs in Soylent is a little more complicated to calculate because we have to factor out fiber, but it’s not hard. In 1.0, a serving of 148g contains 84g of carbs, 9g of which are fiber. So, to get 50g of available carbs, you need 148/(84-9) g-total/g-carbs * 50 g-carbs = 98.7g of Soylent powder. I did some quick verification using USDA info on oat flour and we get the same result if we assume 97% pure maltodextrin. In 1.1, the total mass increased by 3g (1g per serving), and assuming no change in carbohydrates, that means you’d want 149*50/(84-9) = 99.3g of Soylent powder. Keeping in mind that the original values are heavily rounded, you can probably be just as confident if you use 99g of each. For either 1.0 or 1.1, the corresponding amount of oil (based on .66 fl oz per serving) is about 2.64 tsp.

Let us know how it turns out.


My ‘sports drink’ isn’t the only thing I consume on long rides. I also put more than dextrose into my mix. My mix consists of 1/2 cup dextrose, 1/2 cup table sugar, and some amount of salt but I forget the amount off the top of my head. That’s enough mix for 1 gallon of water.

Good idea.

Thank you for the calculations. Not having done this before, I wasn’t sure if that’s all I had to do.

Thanks again.


0.66 fl. oz. Is 4 tsp not 2.64 tsp.

2 fl oz = 4 tbs = 12 tsp

12 / 3 = 4 tsp


I said “based on .66 fl oz per serving”, but we don’t need a full serving for 50g of available carbohydrates. There’s .66 fl oz of oil per 148g of powder. Since we need 99g of powder, we need 99/148 * .66 fl oz = .44 fl oz oil.

.44 fl oz * 6 tsp/fl oz = 2.64 tsp.


This is the Dextrose I have:

Just an FYI.


Paging @CarltonLemley. Weren’t you doing something similar a while back with DIY?


Sorry I missed where you said “a corresponding amount of oil” you are correct.


I just a pomegranate and only protein before hand (tuna, pulled pork, protein shake) each at about 100 calories. after the pomegranate my blood sugar was 200 first reading 17 minutes after first handful of red juicy pouches, and 150,151 the second two taken immediately after the first to confirm (hand washing in between each in case i didn’t wash well enough the first time. from my readings with soylent, I’ve not gone past 120.

The units are mg/dL sorry.
just commenting, do not have diabetes as far as i know. usual wakeup sugar has been 85 -100
it was down to 121 mg/dL after 40 mins.


This morning, I tested my blood sugar after drinking 443 ml (roughly) of Soylent 1.1, which was prepared per instructions: one full pouch, one bottle of oil, and sufficient water to fill the 2-liter pitcher.

This morning’s testing raised a few issues that I need to investigate further.

  1. The testing apparatus I used, it is nearly impossible to remove the testing strips from the bottle without getting my fingers on the working end of the strip. So, contamination seems a real problem.
  2. I may be borderline pre-diabetic. I’m a bit surprised by that, but it definitely warrants further investigation.
  3. Number 2 not withstanding, Soylent 1.1 seams to raise my blood sugar more than I’d like. I may need to investigate my own DIY recipe.

Vital stats: 50-year old, very active male, 5’9", 164 lbs (as of this morning).

Here are the results from this morning’s test:

Fasting:     91
15-minutes:  122
30-minutes:  144
45-minutes:  134
60-minutes:  146
90-minutes:  120
120-minutes: 106

I will test with dextrose tomorrow morning.


I’m no expert, having never monitored my blood sugar and not knowing what normal looks like, but that doesn’t look all that bad.


According to this website: What are Normal Blood Glucose Levels?

After consuming 75 g of glucose, which is 50% more carbs than I consumed, your blood sugar should not rise above 140.

It is, though, the strictest criteria I’ve read, online.


OK, after reading more, it may be that I’ve misunderstood a key sentence on the website I linked to: “Any value between 140 mg/dL and 199 mg/dL during a two-hour 75g oral glucose tolerance test.”

I understood the sentence to mean any value above 140 during the two-hour test. But, after reading other sites, like this one, it apparently means any value above 140 after 2-hours.

If that’s the case, then apparently I’m fine. Though, the test does call for 75 g rather than 50 and of glucose rather than Soylent. Anyway, we’ll find out tomorrow how Soylent 1.1 compares to straight up dextrose.

If someone who knows about blood sugar would weigh in on the results I listed above, it would be much appreciated.


One thing that I forgot to mention that I found interesting about the results, this morning, is the double peak at 30 and 60 minutes. It could be an anomaly or contamination. But, one thought I had is, maybe it is the result of the two carb sources present in Soylent: maltodextrin and oat flour. Thoughts?


@austonst 's approach looks correct to me.

@malachi , thanks for doing this. I’m interested in the results, too.


The double peak is not a concern; a lot of factors come into play - simpler carbs are absorbed quickly, complex carbs later, digestive processes are still ramping up, your body is still mobilizing after sleep and the rush of morning cortisol, etc. Remember, the test is detecting glucose in the blood, specifically - and body is also simultaneously pulling the glucose out of the blood to use it or store it.

As far as worrying about being pre-diabetic - you really have to do a glucose challenge, but your fasting level is safe.

Your glucose came almost back to baseline at two hours, so you’re CERTAINLY not diabetic, and you probably have a healthy insulin response, but you can’t rule out pre-diabetic without a glucose challenge.

There’s a good chance that you just need a little more exercise - how are you in that department? If you don’t exercise, adding a bit of exercise will make you more sensitive to the insulin you produce - and your muscles will suck up the glucose from your blood more quickly, and you won’t see it rise as much.


I was hoping you would weigh in on the topic.

I didn’t think the double peak was a concern, I just thought it was interesting and wondered if it was the result of the two carb sources in Soylent.

I am very active. I’m an adamant cyclist and my bicycle is my main, almost exclusive, form of transportation. During the summer months, I average well over 20 miiles per day. In the winter that will taper off a little bit, but I commute all year.

I do believe that I am in good physical shape, especially cardiovascularly.


Here are the results of this morning’s dextrose test.

             Soylent 1.1    Dextrose
                (443 ml)      (50 g)
Fasting:              91          88
15-minutes:          122         119
30-minutes:          144         123
45-minutes:          134         162
60-minutes:          146         161
90-minutes:          120         151
120-minutes:         106          88


It was hard to read the table (dam formatting ) but your graphic it is clear that Soylent has a lower overall spike in blood sugar even though it peaked sooner an stayed above base line longer. The slower return to baseline would prevent the “sugar crash” some have been concerned with. One question. How quickly did you drink the Soylent and the dextrose? I would love to hear from. @rob on this. Anyone else interested in giving this a try? Nicely done. Soylentpioneer!


OK, your dextrose curve looks good!

Curves after a glucose challenge are supposed to return to baseline (or even temporarily dip below baseline) at about 120 minutes, so I wasn’t sure how to interpret your soylent chart - but with the dextrose curve looking so typical, it makes me think you’re perfectly healthy.

Here’s a reference chart of typical response curves in different conditions (albeit with a standard oral glucose challenge, with the 75 g glucose consumed in four minutes or less)