My experience with Sweeteners


(David Cumming) #1

Just wanted to share my negative experience with artificial sweeteners. I’ve been doing a keto diet for a couple of months now. Had some ups and downs but I’ve kept it pretty clean for the last few weeks. Based on reading so many sources saying that sweetners don’t impact insulin, I decided to incorporate non-caloric sweetners (no sugar alcohols) into my day to day. Suger free jello, syrup for coffee, bit of diet soda with sucralose, gum. The first day, didn’t notice any change. However, on the second and third day, I noticed increasing appetite and low energy (to the point of being larthargic). Before taking sweeteners, I was running 10K per day - on this second and third day, I couldn’t even go to the gym. No matter how much fat I ate, I could not get sustained energy levels. I would eat some macadamian nuts, feel better for 1 hour, then be starving again and weak.
I’m not diabetic so I don’t have any tools to measure so apologies for not having a more scientific post. However, I can say this - I stopped all sweeteners, and within 24 hours I was back to feeling great and having sustained energy along with a normal keto appetite pattern.
This is pure speculation, but if my insulin was being raised by the sweeteners, that would explain the low energy levels, increased appetite, and the inability to have sustained energy levels eating fat.
I just wanted to post my experience so others can consider whether sweeteners may be having unforeseen effects on their keto efforts as well.


I’m curious if you have tried a similar experiment with the sugar alcohols, like Swerve (a combo of Erythritol and Oligosaccharides) or Xylitol? I did one glucose curve a la Richard’s post using Swerve and I did see a dip at the 90 minute mark of my blood glucose, which might indicate an insulin impact. I’ve been wanting to test it again but haven’t had a good opportunity.

I don’t use artificial sweeteners at all for many reasons. It’s interesting how fast you rebounded once off the artificial sweeteners.

(David Cumming) #3

Never done the similar thing with sugar alcohols - maybe in the future I will, but for now, I’ll just get used to not eating sweet things

(Siobhan) #4

Not all sweeteners are the same.
Some have adverse reactions reactions to sucralose and aspartame, sugar free jello and syrups etc tend to have matodextrin and maltitol which are no good.

The ones Ive seen give the smallest effect is erythritol and stevia. Erythritol has had no effect on bg ir insulin in all clinical trials Ive seen.

So perhaps that is why?

(Jan) #5

When I first started limiting carbs, I started eating sf jello, kool-aid, etc, thinking it was “safe”. Then read about maltodextrin, which has a higher glycemic index than straight sugar. (Yep, you read that correctly - look it up!) I cut out anything with maltodextrin & it’s cousin maltose, and saw my fasting bg drop by nearly 15 points overnight. Maltodextrin is EVIL!!! I have no idea why it’s not considered as a carb. (EVIL, I say EVIL!)

(David Cumming) #6

the jello i used was great value it is sweetened using aspartame and acesufame Potassium. I also used Stevia (pure, not truvia) and Sucralose. I couldn’t isolate only one because I was using different products that were already sweetened so yes, maybe one was bad and the others weren’t. I’d have to introduce a single product at a time to really know for sure. thanks for your replies

(David Cumming) #7

I agree, it’s pretty scary how bad some of the so called sugar free products can actually be

(Siobhan) #8

acesufame Potassium (also called ace-k) is metabolized the same as sugar and spikes bg/insulin just as much.
Some have a bad reactiom to aspartame… so I would say maybe later down the road try stevia/erythritol ONLY and do it in a testing environment e.g a glass of water with erythritol, measure bg and how you feel
then do the same with pure water
compare the two results


Xylitol is my AS of choice as to me it tastes the most like sugar and the least fake/bitter. On the low carb cruise Keto Talk episode (#69), Dr. Nally mentioned that while Xylitol does not affect BS, it does cause an insulin response.

From doc muscles website:
"Maltitol, sorbitol and xylitol seemed to be worse offending culprits in this class of artificial sweeteners. They cause an insulin response of about half that of normal sugar (American Journal of Clinical Nutrition, Vol 65, 947-950)."
Here’s the link to the whole post "The Skinny on Sweeteners"

Bummer! Xylitol is expensive anyway, so I’ll stick with erythritol and liquid stevia, or better yet…no AS!


I just finished a 72-hour fast. Broke it with a 12 oz steak and some ghee. Felt fine. Went to the store and picked up some groceries and some “vitamin water” sweetened with erythritol and stevia, drank it and now I have zero energy. I was thinking the fatigue was because my digestive system was working extra hard at digesting steak after 72 hours of not eating. After reading this thread I wonder if it was the "vitamin water. "

(Josie ) #11

Wow- I have heard for years how bad AS are yadda yadda yadda - but I never really let it sink in. I had vsg in April 2016 and have lost so stinkin slow - I also have drank Powerade zero every single day - when I wasn’t drinking Powerade zero I was drinking water with those flavoring packs like crush or Hawaiian Punch etc… I read the link that was shared on a different comment- so my question is-- what can I drink , I know if I have to drink plain water I won’t be getting much liquid in at all. I also drink coffee (was using sweet n low, and then switched to stevia (which isn’t too tasty in coffee ) think I’m going to buy some truvia for it(that sounds like a safer choice) oh and I am brand spanking new here (my first post) and already rambling :joy:

(Sonia A.) #12

You could try squeezing some lemon juice in your water.

(David Cumming) #13

If you want something carbonated, I’ve seen several brands of sparkling mineral water flavored with lemon/lime, even black cherry - they are not sweetened but I think they taste pretty good

(David Cumming) #14

Wow - almost didn’t even notice the acesufame Potassium in the ingredients (I had to google it to even realize it was a sweetner) - just shows how careful you need to be when using products - thanks for the advise

(Josie ) #15

Luckily I gave up carbonation over a year ago- it’s not recommended after weight loss surgery - but I don’t think it actually hurts the sleeve - a couple of times I have had carbonation.


I mostly drink water, water with a squeeze of lemon, or seltzer and flavored seltzer, coffee and tea.

I drink nearly a gallon a day although I do not keep careful track.

One thing, if you do not usually drink water, you may want to try different brands. There are some brands I personally do not like (Evian, Nestle I am looking at you) and others that I find delicious, Poland Spring and Deer Park and Smart Water among others. So try experimenting with different bottled waters or try filtering your tap water to see if it tastes better.

Friends did not believe I could taste the difference so one day we had a taste test and it turns out I can and so can other people but preferences are indiviual

(#inforthelonghaul, KCKO, KCFO) #17

Josie and lijunne,
Fresh mint and cucumbers is a good addition when plain gets really old. You can also crush up a few strawberries and let the water sit for a bit in the fridge, gives a pleasant taste. Herbal teas are oked by Fung for fasting. Those come in many flavors.

(Sonia A.) #18

Great ideas :+1:. I’ll try them. Thank you. :smile:

(Tim W) #19

I won’t say it wasn’t the vita water BUT I also experience some rough energy swings after my first meal to break a fast. I think it may be the body diverting sodium/other “assets” to the digestion process, using up energy that you have not devoted to that process for three days. Once the digestive process is “back up and running” your energy level stabilizes and it’s time to run “like normal”, just for what it’s worth.


I think you’re right. It took me 3 days to get back on track. Next fast, I’ll break it more gently and see if that shortens my recovery.