Update on the Pepsi Max test

Pepsi Max-test

What happens if you drink Pepsi Max? Do the artificial sweeteners affect blood sugar or ketone levels? I’ve just tested it.

As you can see I did quite a few blood tests with my blood sugar and ketone meters: 24 tests during almost six hours. So something interesting happened, otherwise there would have been no reason to keep going for so long. But what happened?

My blood sugar started at about 4,5 mmol/L (80 mg/ml) and my ketones started at about 4 mmol/L. What do you think happened after drinking Pepsi Max?


  1. Kenny
    Not sure, you blurred out the results :P
  2. Jason
    Increased insulin response due to brain signalling a false positive to sugar. Therefore a decrease in blood sugar, perhaps to unhealthy levels, and an end to ketosis?
  3. eddie watts
    the idea of caffeine essentially triggering a reduced fight or flight response causing the liver to dump glucose into the blood stream is interesting.
    read of this before and maybe part of why workout stims contain caffeine even if they do not contain carbs.

    looking forward to results :)

  4. mikael bruusgaard
    we are a small group in Denmark who have made the same experiment with pepsi max and zero. there were no major deflection on blood sugar, but our weight loss stopped when we drank them .. we could not understand. but then we examined sweeteners and found Aspartame which unfortunately has the same effect as sugar when you're talking LCHF. sorry guys dont drink it. and keep far away from anything with aspartame in it
  5. Rae
    Well, its been a long time since I have had to calculate the molarity of a solution. But I can guess just from experience of drinking things with artificial sweeteners in the past as compared with the consumption of sugar the effects.

    Sugar as we know leads to the production of insulin which stores fructose as body fat and tells our brain soon after that we are hungry. I can testify to the fact that when I still drank diet sodas it affected my appetite, making me want to eat more frequently. I believe Jason hit the nail on the head with artificial sweeteners being recognized by the body as a sugar therefore spiking blood sugar and lowering or nullifying ketosis.

  6. Sue
    Out of ketosis and high blood glucose followed by a slump??
  7. mezzo
    Why should we be able to guess? From what I know about the subject people show a wide range of responses. So I am eagerly awaiting the results of your n=1 study.
  8. I believe your body reacted to the false sugar input and produced more insulin at first then got use to effect and stopped responding to false flag.
  9. Diane
    Put me out of my misery and just tell me!!!!!
  10. KNM
    I've recently discovered that I'm allergic to diet drinks, and I'm pretty sure it boils down to the artificial sweeteners. After months of breaking out into itchy and painful hives, I started trying to narrow down the cause. Wheat, soy, eggs, nuts, etc. I went though the obvious culprits and then realized the only drastic change in my diet was switching from regular soda to diet in order to avoid sugar. It's POISON! Never will I drink soda again, nor any "sugar free" beverage like Crystal Light.
  11. John
    I'm guessing an insulin response, reduced blood sugar but an end to ketosis? something unexpected no doubt!
  12. I am one of the lucky ones who has never been fooled by the older artificial sweeteners - it isn't a moral claim: for something like a sixth or a seventh of the population, they just taste ghastly. (I have been fooled by the sugar alcohols, which has been interesting...) Something I find interesting, which isn't talked about, or perhaps widely known, in the LCHF blogs, is that we have sweet receptors in our guts, as well as on our tongues. They are probably there for a purpose, and, given how conservative physiology is, if the receptors on your tongue can be fooled, the receptors in your gut can be fooled. So your gut is saying to your brain "Big load of sugar on board..."
    At a meeting when I didn't have much choice, I unknowingly consumed a glass of sugar-alcohol sweetened grapefruit juice. Even though I didn't like it much, thought it inferior grade, insipid tasting juice, I was driven by some urge to go back and consume MORE! I hate it when it is implied that dieters eat more after an artificially-sweetened soda because they are stupid and have given themselves a free pass. There is something about fooling your body, that makes it want reality to catch up.
  13. Peter
    Wouldn't it be better to test with a diet soda without caffeine ? If you see a spike in insuline levels it could (in part) be from the caffeine or am I seeing this wrong ?
  14. My guess is that the brain sends signals to the body to deal with what it expects to be sugar and caffeine. When the body doesn't have to deal with actual sugar, it reacts and then tries to compensate. It probably then takes a little while 'till the blood sugar and ketone respones level out back to normal. It would be really interesting to see what the results are for caffeine alone and the sweetener alone.
  15. Marcy
    I am lucky as well. The taste of any artificial sweetener has tasted like poison to me, so I have avoided them. However, I do like the taste of Stevia and have been using it. I wonder if you could do a test similar to this with Stevia? Please?
  16. Pavlov rang the bell, the dog salivated. An example of a direct connection between the brain and a physical response. Pepsi Max is the bell. The body reacts to what it expects then gets confused trying to deal with it. I wonder if continual conditioning like this will eventually cause the brain body connection to get permanently screwed up.
  17. Your body reacted as if you had eaten sugar!
  18. nonegiven
    Plain coffee with cream, no sweetening, first thing in the morning can raise me by 30mg/dl. I think it's the caffeine.
  19. J. C. Souto
    I would guess that nothing will happen to the blood sugar (or that it will drop just a little bit because of a little spike in insulin due to the sweet taste). But I am really dying to know what happens to ketones levels: will the sweet taste-induced insulin spike (that should be short lived since it its not followed by the expected increase in blood sugar after a real sweet treat) decrease ketone levels? My guess? A little bit. Tell us PLEASE!!
  20. @Cate "Pavlov rang the bell, the dog salivated..."

    Though in this case the bell rings and the dog does not get the food...really think this depends on how often a person really has sweet foods assuming they completely abstained from sweets this could result in minimum impact. Though given your body would react to this even with some sweet carrots might be hard to "train" your brain to ignore this signal :)

  21. nonegiven
    If I walk by a bakery and smell cinnamon rolls I'll get hungry so just the smell is causing insulin release.
    Reply: #25
  22. Jessica
    Ugh, TWO teaser posts? What is this, a game show?
  23. Helen
    Dude, I thought you were going to tell us. Enough of the games, what was the result???
  24. Demosthenes
    What a waste. The results are meaningless anyway.
  25. getting hungry does not necessarily mean you got an insulin response
  26. As far as I know, pepsi max contains aspartame. According to some studies, aspartame had no effect on insulin level. And since ketone concentration is basically 1/insulin, I bet on the boring outcome that there was no effect.
  27. Sean P.
    The results from this test only tell us either:
    a) The artificial sugar caused the response
    b) The caffeine caused the response
    c) The ultra-palatability of the food caused the response
    d) There was a placebo response because he expected (or wanted) something to happen
    e) The anticipation (and expectation) of receiving food caused the response (so it was nothing unique to just the soda but any food source)
    f) One of the other hundred chemicals in the soda caused the response.
    g) One or more of the above interacted together to elicit a response that would not otherwise happen if each individual component was tested individually

    With the except of d and e, you could still make the conclusion that drinking a Pepsi Max would elicit some form of response but it's impossible to pinpoint the causal factor. However, it's also impossible to know if the response wasn't caused by d and/or e so it's impossible to interpret the results and find the causal agent and you definitely can't conclusively say the response was caused by the Pepsi Max (let alone blaming some singular component of the Pepsi Max for the response).

  28. wickedchicken
    Thats a lot of test strips!Do you change the needle tip each time? ((for my own research purposes I am wondering)). I have the same machine in blood glucose version, but I don't change the needle..... I read it's fine to reuse for a few weeks at a time...??!!! No???
  29. Actually I find Pepsi Max an interesting choice for this experiment. Given it has twice the caffeine of typical diet soda. It also has some added ginseng which probably does not an effect...but still an additional variable. I would like to see the same experiment with coffee or even normal diet soda...if same effect but less significant could make assumption that caffeine has a notable effect.
  30. Michael
    Er ... so, what happened?
  31. Jess
    Your blood sugar will fall because insulin can not distinguish between a real carbohydrate and a sweetener, and your ketones will be transformed to fat and stored, because this is what insulin does. As a result you will feel very hungry because your body will be starving. Question: are all artificial sweeteners equally bad or is aspartan the worst? Thanks
  32. jess
    Ok, maybe a bit too much fantasy about ketones being transformed by insulin (maybe it happens earlier in the metabolic cycle, i don't remember anymore). Sorry. Nice method of presentation by the way, people that tried to guess will not forget the actual result for long time. N=1 is better than n=1000 and aknowledging pepsi for funding.
  33. ridiculous
    well this is pointless - obviously people who visit this actually want to know the effects pepsi max has, possibly due to health worries - not some silly smug little guessing game

    get a life

  34. Gary
    What were the results?????????
    Reply: #35
  35. Peter Biörck Team Diet Doctor
    Hi Gary!

    Here you are:

    What were the results?????????

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