| | The Bitter Truth About Artificial Sweeteners

Author / Leah Kay

All right Diet Diva’s, time to drop some knowledge bombs and crush your little hearts. You think you’re doing yourself a favor trading in your Pepsi Big Gulp for a Diet Coke? Well we’ve got news for you. But I don’t drink Diet sodas, you say. How about that “low sugar” protein bar you just grabbed chock full of sugar alcohols? Or that “healthy” brownie you made with splenda. But this shit has no calories! Can it really be that bad for me?!?

Look, we get it, we’re all human and humans have an uncanny ability to bend the rules to fit our desires. Most of us know that if we stuff our faces with sugar it’s not going to be pretty, but there seems to be a massive misunderstanding when it comes to chowing down on artificial sweeteners. While the occasional splurge on less than optimal food choices is not going to be a problem for an active, hard-charging Power Athlete, the bitter truth is that regularly adding things like xylitol, erythritol, aspartame, and other artificial sweeteners to an otherwise healthy diet creates problems and sometimes is even worse than sugar itself. So step away from the can and feast your eyes on this…


Common artificial sweeteners?

Artificial sweeteners can generally be placed into two categories; Sugar Alcohols (xylitol, sorbitol, erythritol) and Non-nutritive sweeteners (Sucralose, Aspartame, Neotame, Saccharin, Acesulfame potassium).

In general, our bodies were not designed to process these types of artificial sugars and even sweeteners touted as “natural” such as fructose and stevia can present problems. Though they come from plant products (like fruits), sugar alcohols are a hydrogenated, refined and purified form of sugar that’s used as a sweetener. Non-nutritive sweeteners have a different chemical compound than sugar alcohols. They taste sweet, usually much sweeter than standard table sugar, but they don’t provide many calories due to our body’s inability to absorb them. When examining these two types of artificial sweeteners, we can begin to break down why these bad boys have no place in a Power Athlete’s diet.

Immune system dysregulation

A recent study published in the journal Nature found that rodents fed a diet high in artificial sweeteners experienced an increase in gram negative bacterial growth within their gut microbiome. It’s hypothesized that gram-negative bacteria (like E.Coli) actually causes something called endotoxemia at the level of the gut.(1) We’ve learned from a previous post that the intestinal mucosa is permeable or as John Welbourn put it, it’s like an organ made of cheesecloth. The outer membranes of the gram-negative bacteria contain endotoxins and when these bad boys and their cell membrane remnants pass through the intestinal cheesecloth, we get an immune response.

So why does this matter for performance? An overactive immune system can cause such issues as joint pains, thyroid disorder, GI dysfunction and a host of other issues that make performing at an optimal level almost impossible. But perhaps the biggest issue with an overactive immune response is that it creates a state of chronic inflammation which affects the ability to expediently recover and drive accelerated adaptation.

Chronic Inflammation

While inflammation is a natural part of our immune response, it is supposed to be transient. For example, the acute soreness you feel in your muscles after a particularly heavy day on Jacked Street is an example of an acute inflammatory response. The body works to repair the damage inflicted and you become stronger.

You can imagine how your performance would suffer if the body continued to respond even after the tissue healed? But this is exactly what is happening! Not to mention that chronic inflammation is linked to a number of other diseases like metabolic syndrome and cardiovascular disease.

That’s not all folks

So while we’ve established that artificial sweeteners can alter the gut bacteria causing immune system dysfunction and chronic inflammation, the bad news doesn’t stop there. All mice fed artificial sweeteners developed some degree of blood sugar dysregulation! (1) Whoa! I thought we were eating artificial sweeteners because they had no calories and therefore couldn’t be as bad for our blood sugar (and waist line) as real sugar?!? Unfortunately, this just isn’t the case. Poor blood sugar regulation in athletes can not only lead to unwanted fat gain, but also an inability to manage your intensity during your workouts, meaning you could find yourself hitting the wall in the middle of your training.

The bottom line

Trading out your sugar, honey, or maple syrup for artificial sweeteners is not picking the lesser of two evils! The only way to safeguard yourself against these potential health calamities is to reduce your intake of these chemical bad boys. Dessert is still dessert no matter how you slice it and in many cases, the real deal is better for you than the fake stuff. That’s the truth, the whole truth and nothing but the bitter truth.

1 Suez, J,  Korem, T, et al. Artificial Sweeteners Induce Glucose Intolerance by Altering the Gut Microbiota. Nature, 2014;514(7521)181-6.

Share this article

Leah Kay

Former collegiate volleyball player and 7 year competitive CrossFitter. 6x CF regional qualifier and 1x CF Games qualifier. Began coaching CrossFit in 2009 while working towards a Bachelor's in Nursing. Studied functional medicine through the American Academy of Anti-Aging in 2013 with specific emphasis on nutrition and hormone regulation. Continues to blend love of coaching and wellness as Head Trainer and Co-Owner of CrossFit Katy and Functional Nutritionist at Specialty Healthcare and Wellness in Houston, TX.


  1. TomC on October 26, 2016 at 11:51 am

    Great article. I never hear much about stevia, does the same deal apply? I often hear that whilst aspartame etc are bad stevia is ok (…because it’s natural!) ..but I’m suspect. What’s the deal with it? Thanks a lot

  2. […] Feature Image Source: Power Athlete […]

Leave a Comment


Never miss out on an epic blog post or podcast, drop your email below and we’ll stay in-touch.

  • This field is for validation purposes and should be left unchanged.