Sucralose Keto Sweetener: Is This Keto-Friendly Sugar Alternative Too Good to Be True?

There’s a wide variety of sugar substitutes to choose from when you’re on the keto diet or any low-sugar diet. Stevia is a natural sweetener from the stevia plant and even safe enough for kids and pets (if they like to sneak food off your plate). Erythritol is a sugar alcohol found in fruits like melons and pears, another natural alternative. However, sucralose (the key ingredient in Splenda) is an artificial sweetener: does that make it better or worse? Is sucralose keto sweetener an option for this low-carb diet, or is it better to go all-natural when trying to replace refined sugar? We have the details on how sucralose is processed and what that means for your health and your keto diet. 

Say “So Long” to Sugar

You know refined sugar is bad for you: it spikes your blood sugar levels and is processed free of the natural benefits found in raw sugars, brown sugar, and blackstrap molasses. But did you know that white table sugar is actually addictive, triggering the same pleasure centers of the brain that cocaine does? That makes it harder to quit sugar than many expect when they first try. Just as when attempting to quit caffeine, weening yourself off of any kind of substance your body has become dependent on is uncomfortable and can lead to backsliding just to satisfy the craving and get on with your day. 

Switching to decaf coffee helps those quitting caffeine replace the ritual surrounding coffee, just as finding the right healthy sugar alternative makes it much easier to ditch sugar. Whether you’re on the ketogenic diet or quitting sugar to lower your blood sugar levels and avoid the onset of type 2 diabetes, saying goodbye to sugar is a healthy choice.

What Is Sucralose?

Sucralose is actually made from sugar in a chemical process first discovered accidentally by researchers Shashikant Phadnis and Leslie Hough in the 1970s. One day Phadnis was told to test the powder they’d made, misunderstood and thought he was meant to taste the powder, found it to be tooth-achingly sweet, and enlisted Hough to try it too. Hough immediately and delightedly dubbed it Serendipitose, after which it was developed into the Splenda product by companies Tate & Lyle and Johnson & Johnson for eventual worldwide distribution.

Introduced to the United States in 1999, Splenda packets are still found in diners all across the land, and it’s used in food products and baking recipes across the globe. Sucralose is up to 700 times sweeter than sugar, with no bitter aftertaste, making Splenda an enduringly popular product. But is it keto-friendly?

Sucralose: Keto-Friendly Sugar Alternative or Snake Oil?

Though it isn’t a natural sugar substitute, that doesn’t mean sucralose (marketed as the popular product Splenda) isn’t a useful tool on the low-carb keto diet. Like the aspartame found in diet sodas and the saccharin found in canned fruit and Sweet’n Low, it’s an artificial sweetener that does the job of stimulating your sweet taste receptors while making your food and beverages sugar free. 

Are there any benefits specific to sucralose or any side effects to be aware of? We have the full details below.

The Health Benefits of Sucralose

Here are the best highlights of sucralose.

1. Neutral on Weight Loss

Studies show that artificial sweeteners like sucralose are either completely neutral when it comes to body mass index (neither prompts weight gain nor weight loss), or they help contribute modestly to an overall weight-loss effort by replacing sugar (up to an average of 1.7 pounds difference). If your primary use for a sugar alternative is to lose weight, sucralose will not interrupt your goals and may even help them.

2. Better Than Table Sugar for Blood Sugar Levels

Another benefit of sucralose includes the same benefits you can get from any alternative to real sugar like agave syrup (a liquid form of natural sweetener), allulose (found in figs and raisins), or Truvia brand name products (made primarily with stevia extract): they’re low-carb sweeteners that can effectively replace regular sugar. This is good for your blood glucose levels, and lowers your risk factors for metabolic disorders like obesity, diabetes, and heart disease.

Any alternative from monk fruit extract to sorbitol (a sugar alcohol found in sugar-free maple syrup) is better than consuming high-fructose corn syrup or refined sugar, especially on a low-carb diet. But these products are not all created equal. The best sweeteners won’t have a bitter after taste or uncomfortable side effects like bloating or laxative-induced diarrhea, for example. Where does sucralose fall on that spectrum?

The Side Effects of Sucralose

There are subtle downsides to sucralose and Splenda.

1. Sucralose vs. Splenda on Carb and Calorie Count

Though sucralose and Splenda are safe to eat, the Splenda blend also contains additives like dextrose (glucose), maltitol, and maltodextrin, which do contribute minimally to your net carbs (1 gram per packet of Splenda) and therefore aren’t ideal for staying in ketosis. 

Likewise sucralose alone is a zero-calorie sweetener, but the additives in Splenda contain at least 3 calories per packet—a minimal amount that nevertheless may have an adverse impact on a diet as precise as keto. 

2. Blood Sugar and Insulin Resistance

Sucralose itself rates a zero on the glycemic index, so in its pure form it has virtually no effect on your insulin levels or blood sugar. However, that isn’t a universal truth, as one study from 2013 found that obese participants who didn’t consume artificial sweeteners regularly experienced a 20% elevation in insulin levels and a 14% spike in blood sugar levels with sucralose.

This result is not seen in studies on people within healthy weight ranges who regularly consume sucralose, but it is indicative that sucralose does not have a perfectly zero impact on insulin and blood sugar. Long story short: sucralose may raise blood sugar levels and influence insulin production; it depends on who is consuming it.

3. Baking and Heat Stability

While Splenda and sucralose can be used in baking, some studies show that at high temperatures a chemical breakdown occurs that could produce harmful compounds called chloropropanols, potentially toxic substances linked to higher risk of certain cancers. Research is still inconclusive, but baking at temperatures above 350 degrees Fahrenheit (120 degrees Celsius) could cause thermal degradation.  

Sacre Bleu, Sucralose!

When it comes to keto sweeteners, we recommend sticking with products that are as natural as possible, like Swerve brand sweeteners (with erythritol), monk fruit sweetener, or xylitol (a naturally occurring plant alcohol). While the made-from-sugar alternative that is sucralose does serve as an effective sugar replacement and is generally neutral in regards to weight loss, products like Splenda have additives that give it a carb, calorie, and GI impact that isn’t worth your time if you’re working to maintain a ketogenic diet. Plus, the dangers of thermal degradation during baking that could introduce a possible cancer-causing toxin into your food seem an unnecessary risk when there are better, more natural alternatives to sugar.