Artificial sweeteners are a bit of a tricky subject when it comes to the keto diet.

People often ask if consuming sucralose on keto is a bad idea?

Will sucralose take you out of ketosis?

This article will take a look at the research on artificial sweeteners like sucralose to help answer these questions and determine which zero-carb sweeteners are best for keto.

There are so many artificial sweeteners in foods and drinks these days, usually under the guise of products with the words “lite” and “diet” in the name (e.g. Diet Pepsi, Diet Mountain Dew, etc.).

Unfortunately, the misinformation about artificial sweeteners is widespread.

On social media and TV news outlets, you’ll come across articles and videos demonizing sugar substitutes and even claiming they cause cancer.

Let’s be clear here: there is not a single study suggesting that artificial sweeteners cause cancer in humans.

In fact, human clinical evidence has found no causative or correlational relationship between artificial sweetener consumption and cancer. [1]

Does this mean all artificial sweeteners are keto-friendly and healthy?

Not necessarily.

Some research suggests that artificial sweeteners can cause weight gain, but this claim seems a bit spurious. There are flaws and confounding variables we need to consider before labeling things like sucralose and aspartame as being “unhealthy”. 

Read on as we take a deeper look at artificial sweeteners on keto and if you should use them for weight management.

Artificial Sweeteners and Weight Gain

Some longitudinal data suggest that people who consume large amounts of artificial sweeteners have a tendency to gain more weight than those who don’t consume artificial sweeteners. [2]

In other words, there seems to be a correlation between weight gain and artificial sweetener consumption. 

However, correlation is not the same as causation.

A correlation denotes a connection between two (or more) variables.

This is far different from a causal relationship between variables. If you aren’t too savvy about interpreting data and the findings of studies, distinguishing between correlation and causation can be somewhat tricky. 

For example, according to surveys, roughly half of the people who read nonfiction novels overeat whenever they are angry.

In comparison, only 38% of people who don’t read nonfiction have the tendency to overeat when they are upset. 

What does this ultimately tell us?

That reading nonfiction causes 1 out of every 2 people to overeat when they angry? 


It simply tells us there is a weak and likely meaningless connection between two totally unrelated variables. You can draw these types of correlations between tons of variables, whether they are directly related to each other or not. 

Now, does that mean that correlations are inherently meaningless? Certainly not.

When you find a correlation in a large enough sample population between variables being studied, then there may be some significance and underlying truth to it.

Correlation Between Artificial Sweeteners and Weight Gain

Ultimately, we need to approach correlational findings with caution.

There are so many factors to consider before drawing a conclusion when it comes to data.

  • How was the study set up?
  • Did the researchers have a placebo treatment?
  • Were the participants aware of which treatment they were given?
  • Were the participants in good health (metabolically) before the study?
  • How many participants were there? 

Those are just a few factors that alter the bias of data.

The issue with the research that has found a correlation between artificial sweetener consumption and weight gain is that the studies are not controlled, they are observational.

This means the researchers had no say in what the study participants were doing for major lifestyle influences on body weight (e.g. calorie intake, exercise habits, etc.).

If we really want to ascertain the impact of artificial sweeteners on body weight, multiple well-controlled studies are needed. These studies should control for calorie intake, diet composition, exercise, and much more. 

Observational studies just don’t cut it for determining the healthfulness of artificial sweeteners. 

There’s just way too many uncontrolled factors at play in current observational studies to say that artificial sweeteners caused subjects to gain weight. 

We also need to consider that the majority of the U.S. population is overweight (if not obese).

This means most people are overeating.

When an obese person is told they have type-2 diabetes, and they need to cut back on sugar, they immediately switch to diet soda.

And don’t get me wrong, you have to cut calories whenever possible if you’re obese and/or a type-2 diabetic, so diet soda is useful in that way.

However, using these individuals in cohort studies tends to skew the data on artificial sweeteners and weight gain.  

Are Artificial Sweeteners Bad for Controlling Appetite?

The working hypothesis behind these findings is that artificial sweeteners cause people to crave sweets and overeat.

Your brain, especially the hypothalamus, is one of the major control centers of your appetite. When you eat or drink something sweet, your brain typically responds by increasing dopamine production (which drives reward-based behaviors).

In turn, this may cause you to continue eating/drinking to keep “satisfying” your brain, so to speak. Is this a bad thing? Well, yes and no. 

When you consume food or beverages that contain calories, your body senses that it’s getting full and secretes satiety hormones like cholecystokinin (CCK) and leptin.

On the contrary, since artificial sweeteners don’t contain (significant) energy, your body doesn’t secrete satiety signals when you consume them. Hence, you don’t feel full and may be more likely to crave actual calorie-containing sweets

Artificial Sweeteners in Supplements: Good or Bad?

Artificial sweeteners are typically used to flavor and sweeten dietary supplements like pre-workouts and protein powder.

Is this a good thing or a bad thing for keto?

In reality, it’s not going to make a big difference either way, mainly if the non-caloric sweetener being used is sucralose, stevia, or monk fruit.

Some people argue that artificial sweeteners are harmful to ketosis because they increase insulin, which we will discuss more in the next section. 

Do artificial sweeteners increase insulin secretion?

Surprisingly, there is no contemporary research (that I’m aware of) suggesting that artificial sweeteners increase fasting insulin levels in humans.

There is limited research that shows Ace-K (acesulfame potassium) stimulates a mild increase in insulin when infused in rodents. [3] 

(It’s safe to assume that you’re not a rat and you don’t inject large amounts of ace-K into your body, at least I hope that’s the case…)

Furthermore, after converting the dose of ace-K the rodents were given, it would be the equivalent of an adult human consuming 30 12-oz cans of diet soda daily.

The key point is don’t drink two and a half dozen 12-oz cans (360 oz) of diet soda per day, and your insulin levels will be fine.

Heck, if you could somehow manage to drink 360 oz of water per day you would be peeing every 10 minutes.

Moreover, there is a thorough body of clinical research examining the effects of artificial sweeteners on the human endocrine system. This research shows absolutely no conclusive evidence to suggest that they are harmful in moderation. [4]

It’s disconcerting to think that many people scoff at me when I tell them I enjoy a daily can of Diet 7-Up and the occasional sugar-free energy drink.

They usually say something along the lines of “Diet soda is super bad for you, I read an article about it the other day…” (ironically saying this to me while they are guzzling down a beer and/or smoking a cigarette).

Where is the evidence that this is the case? It’s simply doesn’t exist; trust me, I’ve looked long and hard! 

Are artificial sweeteners healthy or unhealthy?

This begs the question:

“Is there anything unhealthy about artificial sweeteners?”

I probably sound like I’m sponsored by Splenda at this point, but I assure you that everything thus far is based on research and impartial. 

The main thing to remember with artificial sweeteners and things like sucralose on keto is that the difference between medicine and poison is in the dose.

If you really want to, you can literally hydrate yourself to death with water – the most essential molecule for our survival.

By the same token, you can safely ingest cyanide in small amounts. In fact, cyanide is naturally present in apple seeds.

The same principle applies to artificial sweeteners: there’s a healthy amount you can consume, and there’s also an unhealthy amount (i.e. excess).

Is Stevia Natural or an Artificial Sweetener? What about Monk Fruit?

Actually, both stevia and monk fruit are natural sweetener sources. Stevia is a plant that contains a naturally sweet, non-caloric compound known as steviol glycoside (stevioside).

Stevioside is about 150 times sweeter than table sugar (sucrose), but it does not impact blood sugar or insulin levels. 

Monk fruit (Luo han guo) is a small melon native to southeastern Asia, containing compounds similar to steviol glycoside known as mogrosides.

Mogrosides are about 200 times sweeter than table sugar and, like stevioside, do not impact blood sugar or insulin levels.

While many people may think stevia extract and monk fruit extract are artificial sweeteners, they are in fact as organic as any other natural sugars.

In fact, both stevia and monk fruit have been shown in to increase insulin sensitivity and benefit gut health in humans. [5] Recent evidence suggests that artificial sweeteners may actually weaken the gut microbiome.[6]

Sucralose on Keto: Is It OK to Use?

In general, sucralose on keto is fine. Pretty much every modern powder-based supplement contains artificial sweeteners – usually sucralose.

The good news is you can consume sucralose on keto without fear that it will impact your cravings or insulin levels in a negative manner. (Again, moderation is key.)

Moreover, some supplements are great for supporting healthy appetite regulation. For example, the exogenous ketones in Team Keto FUEL are well-known to reduce appetite by increasing satiety signals like CCK.[7]

Artificial Sweeteners on Keto: Tips to Follow

Given the correlational findings between artificial sweeteners intake and weight gain, many people are quick to assert that consuming sucralose on keto is a bad idea for weight loss and staying in ketosis.

However, the current evidence doesn’t seem to suggest that consuming sucralose (or any other mainstream artificial sweetener) in moderation is unhealthy.

There is a working hypothesis that artificial sweeteners cause people to crave sweets and overeat, but this is speculative at best.

Lastly, more research is currently underway to uncover the impact of artificial sweeteners on the gut microbiome, which we will be sure to cover in a future blog post here on BioKeto. 

As mentioned earlier, stevia and monk fruit, which are technically natural non-caloric sweeteners, may actually support gut health and insulin sensitivity.

Tips to follow

  • The majority of your artificial sweetener intake on keto should come in the form of pure stevia extract or monk fruit extract.
  • When choosing a dietary supplement, make sure the main sweeteners it has are stevia, monk fruit, and/or sucralose. Aspartame and certain sugar alcohols are ok in smaller amounts.
  • Limit your intake of diet soda (it’s okay in moderation, though).
  • Replacing sugar-free drinks and sugar-free foods with their sugar-containing counterparts is not any healthier or better for your longevity, nor is it good for staying in ketosis. In other words, if you have to choose between “real” Mountain Dew and Diet Mountain Dew, choose the latter.


[1] Weihrauch, M. R., & Diehl, V. (2004). Artificial sweeteners—do they bear a carcinogenic risk?. Annals of Oncology, 15(10), 1460-1465.
[2] Malik, V. S., Schulze, M. B., & Hu, F. B. (2006). Intake of sugar-sweetened beverages and weight gain: a systematic reviewThe American journal of clinical nutrition84(2), 274-288.
[3] Zheng, Y., & Sarr, M. G. (2013). Effect of the artificial sweetener, acesulfame potassium, a sweet taste receptor agonist, on glucose uptake in small intestinal cell linesJournal of Gastrointestinal Surgery17(1), 153-158.
[4] Pepino, M. Y. (2015). Metabolic effects of non-nutritive sweetenersPhysiology & behavior152, 450-455.
[5] Goyal, S. K., Samsher, G. R., & Goyal, R. K. (2010). Stevia (Stevia rebaudiana) a bio-sweetener: a reviewInt J Food Sci Nutr61(1), 1-10.
[6] Brown, R. J., & Rother, K. I. (2012). Non-nutritive sweeteners and their role in the gastrointestinal tractThe Journal of Clinical Endocrinology & Metabolism97(8), 2597-2605.
[7] Chearskul, S., Delbridge, E., Shulkes, A., Proietto, J., & Kriketos, A. (2008). Effect of weight loss and ketosis on postprandial cholecystokinin and free fatty acid concentrations. The American journal of clinical nutrition, 87(5), 1238-1246.