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Is Splenda Keto? And What are Splenda’s Effects on Health?


Since its approval in 1998, Splenda has become a staple in many people’s diets.


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The popularity of Splenda and similar products reflects a growing awareness that consuming processed sugar is unhealthy.

However, while reducing your sugar intake is an excellent idea, replacing it with artificial alternatives like Splenda may not be wise after all.

Even though over 20 years have passed since its approval in the United States, many questions remain concerning its safety and effectiveness as a sugar substitute.

In this article, we’ll look at what the current research says about Splenda’s potential health effects and how keto-friendly it really is.

What Is Splenda?

Splenda is the commercial brand name for sucralose, an artificial sweetener made from table sugar. Sucralose is about 600 times sweeter than sucrose (table sugar).

To make sucralose, chlorine is added to sugar (sucrose) molecules using a chemical process. This way, the sugar cannot cross into the bloodstream and therefore should not cause a rise in blood sugar levels, at least in theory.

Since sucralose cannot be metabolized by the body, Splenda is advertised as a zero-calorie sweetener. However, you’ll soon see why this is not entirely accurate.

Is Splenda Keto?

Splenda is sold as a zero-calorie sweetener. As a result, many people also assume it must be keto-friendly.

However, there’s a very good reason to be skeptical about these claims.

The sweetness in commercially available Splenda powder is attributed to sucralose. Sucralose is indeed a zero-calorie zero-carb sweetener.

However, the bulk —literally — of commercial Splenda is actually made up of dextrose and maltodextrin. In other words, the maker of Splenda combines dextrose and maltodextrin powder with sucralose to give it the equivalent volume of table sugar (that’s why you can mix it like table sugar, instead of using 600 times less Splenda versus sugar).

Dextrose is just another word for glucose. Glucose is the simplest carbohydrate, meaning it’s absorbed into the bloodstream without needing any additional breakdown during digestion.

Maltodextrin is a form of carbohydrate that has a glycemic index higher than that of glucose.

The glucose and maltodextrin in Splenda contribute about 3.4 kcal per serving.

You may wonder why Splenda is able to say that their product has zero calories even if it’s not true. The reason is that the FDA permits food companies to “round down” and label products as zero-calorie if they contain less than 5 calories per serving.

Now, back to the question of whether Splenda is keto or not.

Splenda contains a gram of sugar per serving, which won’t end ketosis all by itself, but your body doesn’t get to “round down” if you consume multiple servings — hidden sources of carbohydrates do add up, and the main point of keto is avoiding added sugars.

The verdict: You can technically consume Splenda in limited quantities, but it’s not recommended for a healthy keto diet. Overdoing it is likely to kick you out of ketosis.

Reasons Why You May Want To Avoid Splenda

While Splenda is technically allowable on keto, it’s still not the best option when it comes to keto sweeteners.

Cancer Risk

With artificially made foods like sucralose, there’s always a question of how they affect the body with long-term use.

When there’s doubt about the safety of a food product, investigators sometimes carry out studies even after its initial approval.

The ideal way to determine if the product is safe for humans is to look at a large group of people who have used it for a long time. Unfortunately, no one’s conducted such a study yet.

One small study found that people who used four packets (4 grams) per day of an artificial sweetener for an average of 5 years have a significantly increased risk of thyroid cancer compared to those who don’t[*]. While that study included sucralose, it didn’t distinguish between sucralose and other common artificial sweeteners. However, the results still aren’t exactly reassuring.

In a 2016 Swiss study, relatively high doses of Splenda resulted in elevated cancer risk when administered to male mice[*]. These results have not been replicated in humans, and humans are unlikely to consume that much sucralose.

Splenda Increases Blood Glucose Levels

While sucralose is likely not absorbed in the gut, it may still trigger an increase in blood sugar and insulin levels.


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A 2018 study showed that sucralose, although considered “metabolically inactive,” has an effect on blood glucose and insulin levels[*]. Scientists believe that sucralose increases insulin production by triggering the release of the hormone glucagon-like-peptide 1 (GLP-1)[*].

Some studies have found conflicting results showing that sucralose has no effect on GLP-1 production and therefore does not affect insulin levels[*].

Even if sucralose had no effect on your blood glucose and insulin levels, it’s not the only ingredient in Splenda. Keep in mind that by ingredients, over 90% of Splenda is dextrose (glucose) and maltodextrin, two of the highest glycemic index carbs.

An often ignored but crucial effect of sucralose is its effect on insulin sensitivity. Sucralose has been noted to reduce insulin sensitivity in both diabetic and non-diabetic individuals[*].

This is also problematic because sweeteners are often marketed to people with diabetes who already tend to suffer from insulin resistance.

Splenda May Cause Weight Gain

The relationship between artificial sweeteners and body weight is confusing, to say the least. Studies have found that people who use artificial sweeteners tend to have higher body weights than those who don’t[*].

The exact reason artificial sweeteners may cause weight gain is not understood. Some of the suggested mechanisms include:

  • Increasing the rate of intestinal glucose absorption[*]
  • Signaling beta cells in the pancreas to produce insulin[*]
  • Altering sweet taste receptors in the gut, which may increase sweet cravings[*]

Another possibility, according to some researchers, is that people who use artificial sweeteners may eat more to compensate for the fact that they are not getting any calories from their sugar-free foods or drinks[*].

Splenda Affects Gut Bacteria

The effect of sucralose on the gut microbiome in humans has not yet been studied extensively, but the effects in mice are concerning.

In one study, researchers fed rats sucralose for six months at a dose equal to the human acceptable daily intake. The sucralose-fed rats not only had altered microbiomes but also showed signs of chronic liver inflammation[*].

In another study, 12 weeks of Splenda consumption lowered levels of lactic acid bacteria and bifidobacteria (both known to be beneficial) in the rodent gut[*]. Finally, sucralose is bacteriostatic, meaning it also inhibits the growth of certain bacteria[*].

Cooking With Splenda May Be Dangerous

Splenda encourages customers to cook and bake with their products. This may pose some risk to consumers as the effects of heat on Splenda under different conditions are not fully understood.

The FDA states that sucralose is heat stable up to temperatures of 450 0F or 232 0C. This only applies when Splenda is heated alone, which is rarely the case in cooking.

This study found that in the presence of glycerols (a component of fats), heating sucralose yields potentially cancerous chemicals known as chloropropanols[*].

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What Are The Best Sweeteners For Keto?

If you’re feeling disillusioned about Splenda, there’s good news. Fortunately, there are still a handful of natural, sugar-free sweeteners that are both keto-friendly and safe to use.

First, a quick recap of what to avoid when it comes to sweeteners. On the ketogenic diet, nutritive sweeteners like regular sugar, honey, maple syrup, agave nectar are all out of the question. Most sugar alcohols, including maltitol, sorbitol, and xylitol, are low carb and calorie-free but are known for having side effects like bloating.

All that said, there are still three proven options that are not only completely natural but also suitable for the ketogenic diet.


Stevia is a natural sweetener obtained from a plant of the same name. Not only is the sweetener actually sugar-free, but it also provides health benefits like improving blood sugar control* and symptoms of metabolic syndrome[*].    Stevia also has the following potential benefits:

  • It may decrease inflammation[*]
  • It lowers insulin resistance in individuals with type 2 diabetes[*]
  • It reduces oxidative stress through antioxidant activity[*][*]
  • It protects dental health*

Monk Fruit Extract

Many people love the taste of monk fruit, describing it as the closest thing to real sugar. This unique sweetener has been used in Asian cultures as a sugar alternative for centuries.

Like stevia, monk fruit is zero-calorie, zero-carb, and may even have some health benefits like reducing oxidative stress and inflammation[*].

For these reasons, all sweet Perfect Keto products use stevia and monk fruit as sweeteners.

The Takeaway

Splenda is neither a zero-calorie nor a keto-friendly sweetener. It’s able to cause an increase in blood glucose and insulin levels. It also contains sugars, glucose and maltodextrin.

There still remain concerns about the safety of Splenda, especially when used in cooking. Safer and more keto-friendly sweeteners like stevia and monk fruit exist and are becoming more popular as customers become more aware of the downsides of Splenda.

This may explain why Splenda sales are declining[*] in the states and in the world at large.


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If you’re looking for a keto-friendly sweetener to use, opt for natural and keto-friendly options like stevia and monk fruit instead.


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