Many people are trying to cut down on sugar these days.
That said, some people still like to drink sweetened coffee or have a sweet treat from time to time.
While sweeteners are not specifically “healthy,” some choices are indeed better than others.
This article examines the most popular sweeteners, their benefits and drawbacks, and whether they are a good fit for low carb and keto diets.
Following this, we will answer the question; which is the best low carb sweetener?
What Are Sweeteners?
Sweeteners are simply food additives that sweeten our food.
Sugar is the most popular – both in homes and within the food industry.
However, various studies have shown harm from sugar intake, and many people are now looking for alternatives.
Notably, sugar plays a detrimental role in oral health, and it is the leading cause of tooth decay in children (1).
Increasing amounts of evidence also suggest that sugar may play a causal role in the rising prevalence of obesity (2).
As a result of these health concerns, various sugar-free and low carb sweeteners have become popular.
These sweet-tasting substances can be bought in their pure form for use at home, and they have many different applications.
For example, many people use them for sweetening coffee or as a replacement for sugar in baking recipes.
Types of Sweetener
There are four main types of sweetener;
- Artificial sweeteners
- Natural sweeteners
- Sugar alcohols
- Caloric sweeteners
Artificial sweeteners are sweet-tasting, non-caloric food additives that have synthetic origins.
Examples include aspartame and sucralose.
Aspartame is a common ingredient in many processed foods, particularly Diet Coke and Diet Pepsi.
Natural sweeteners are non-caloric compounds originally derived from plants.
Examples include powdered stevia (from stevia leaf) and monk fruit extract (luo han guo).
It should be noted that calling these sweeteners ‘natural’ is arguably misleading.
Yes, stevia leaf is natural… but heavily refined white powder is not.
Sugar alcohols are industrially produced sweeteners derived from sugars in food.
If you are wondering about the name ‘alcohol’, this is because the chemical structure of sugar alcohols is similar to alcohol.
Although sugar alcohols do contain carbohydrate, these carbs are neither absorbed nor metabolized by the body.
Some people believe caloric sweeteners such as honey, maple syrup and agave syrup to be healthier choices than regular sugar.
Although some of these calorie sweetening options may provide some beneficial elements, sugar is still sugar.
Artificial Low Carb Sweeteners
We shall start by analyzing some of the most popular artificial sweeteners; aspartame, saccharin, and sucralose.
Aspartame is a controversial artificial sweetener manufactured initially by Monsanto, and it is approximately 200x sweeter than sugar.
You may also know it by commercial names including Nutrasweet and Equal.
While there are many Internet claims linking aspartame to health problems like cancer, the available research does not support these assertions (3).
- Aspartame is a zero-calorie (in regular doses) sweetener and has a rating of zero on the glycemic index (4).
- Tastes a little bit like sugar, and people generally enjoy the taste.
- Although aspartame tastes similar to sugar, it does have a slight chemical aftertaste that some people dislike.
- While detrimental effects in humans have never been proven, there are possible mechanisms for how aspartame may contribute to inflammation (5).
- Aspartame is not safe for people with phenylketonuria; a rare condition that impairs absorption of the amino acid phenylalanine, causing it to build up in the body (6).
See this full guide to aspartame for more information.
Otherwise known as ‘Sweet’n Low,’ saccharin is a non-glycemic and zero-carb artificial sweetener.
Saccharin is 300x sweeter than sugar.
- Since saccharin is so sweet, only small amounts are necessary, making it cheap and convenient.
- Saccharin has a strong and bitter aftertaste. For this reason, it often comes mixed with other ingredients.
- Saccharin appears to be a weak carcinogen and causes bladder cancer in rats, but there is no proof of harm in humans. However, there is no conclusive proof that saccharin is not carcinogenic to humans either (7).
Sucralose is a carb-free sweetener commercially packaged as ‘Splenda.’
To make sucralose, chemists take regular sugar and replace three hydrogen-oxygen groups with three chlorine atoms.
Notably, sucralose is much sweeter than other popular artificial sweeteners and is roughly 600 times sweeter than table sugar.
Like other artificial sweeteners, sucralose contains no calories, and it has a zero score on the glycemic index.
- Some people prefer the taste compared to other artificial sweeteners.
- Zero calories, no carbs, and zero-glycemic.
- Sucralose may have an effect on blood-glucose (8).
- Some people find sucralose has a strong chemical aftertaste.
- Using sucralose at high temperatures appears to cause the sweetener to break down into toxic compounds (9).
Natural Low Carb Sweeteners
In this next section, we will look at the various “natural” low carb sweeteners.
4) Monk Fruit
Otherwise known as ‘Lo han guo’ (or longevity fruit), monk fruit is native to South-East Asia.
This low carb sugar substitute is non-caloric, zero-glycemic and it contains zero carbs.
Concerning the taste, it may be 100x to 250x sweeter than sugar, depending on the particular extract.
- Arguably the most ‘natural’ non-caloric sweetener. The extract is derived from dried fruit.
- Monk fruit has no impact on blood glucose or insulin levels (10).
- The taste of monk fruit comes from the sweet taste of a class of antioxidants they contain called mogrosides, and it is not related to sugar (11).
- Monk fruit extract is relatively new and there is no extensive research in humans. It appears to be safe, but more research is necessary.
- More expensive than other sweeteners.
See this complete guide to monk fruit for more information.
Allulose is a relatively new “natural” sweetener that came to market courtesy of the sugar industry behemoth, Tate & Lyle.
The production formula of this sweetener is “proprietary,” which means the methods behind its production are relatively secretive.
However, we do know that allulose is made via the enzymatic conversion of fructose from corn.
See this review of allulose sweetener for a full evidence-based guide.
- This sweetener appears to be very safe. From initial studies, it seems to improve blood sugar regulation with no adverse effects of any kind.
Stevia refers to the low carb sugar substitute made by extracting the sweet-tasting steviol glycosides from the Stevia rebaudiana plant.
Stevia is non-caloric, and it is approximately 300x sweeter than table sugar in its extract form.
Although it has the ‘natural’ image, stevia is usually highly-refined. After all, it is originally a leaf – not a white powder.
This refined version of stevia may come as a granulated powder or liquid drops.
However, we can also use stevia in its whole-leaf, unprocessed form, which has a much milder taste and is not as sweet.
- Stevia is generally seen as a safe sweetener, and there are no noteworthy negative studies.
- The whole leaf form of stevia is unprocessed and the most ‘natural’ sweetening option.
- Stevia does not adversely affect blood glucose levels. In fact, a trial showed it may even lower them (12).
- Some highly-processed versions of stevia use solvent extraction methods and chemical flavorings. Although this itself doesn’t mean stevia is particularly “bad”, the ‘natural’ marketing might be misleading.
- Some people dislike the aftertaste of stevia.
After only recently achieving ‘generally recognized as safe’ (GRAS) status, at this point tagatose is a little-known low carb sweetener.
Tagatose is 92% as sweet as sugar and has no glycemic effect, with a score of 3 on the glycemic index.
- Initial trials show that tagatose has a range of health benefits, and it has shown promise as a potential treatment for type 2 diabetes – even decreasing blood glucose levels.
- Unfortunately, like with many other sweeteners, digestive problems are a side effect following high levels of intake.
We will now review some of the most commonly used sugar alcohols, including erythritol, maltitol, xylitol and Swerve Sweetener.
Maltitol is a commonly-used sugar alcohol, and it has approximately 90% of the sweetness of regular sugar (13).
However, maltitol does contain carbohydrate and calories, and it has a score of 36 on the glycemic index.
- Tastes just like regular sugar, but it has fewer carbs and calories, and a lower glycemic impact.
- Good for oral health – maltitol does not promote tooth decay.
- Contains carbohydrate and it will raise blood-glucose levels.
- Maltitol often causes side effects such as bloating, diarrhea and gas. Effects such as these may be more intense for people with irritable bowel syndrome (IBS).
Erythritol is an interesting and widely used sweetener.
Similar to maltitol, erythritol is a sugar alcohol, but it has a much lower glycemic index score of only 1.
Although erythritol contains carbohydrate, it is non-fermentable in the gut, and it does not affect blood glucose levels.
Erythritol is approximately 70% as sweet as sugar. As a result, slightly extra amounts of erythritol will be necessary for the same sweetness level as sugar (14).
- Good for dental health – does not harm teeth or contribute to plaque buildup. Additionally, studies have even shown erythritol to decrease plaque (15).
- Has no impact on blood glucose, and based on current evidence, there are no safety concerns.
- Erythritol works as a straight one-for-one sugar replacement.
- Can be used at heat, making erythritol one of the best low carb sweeteners for baking.
- Consuming high amounts of erythritol can lead to gastrointestinal distress for some people (16).
Xylitol is one of the most popular low carb sweeteners, and it has a minimal glycemic impact (and a GI score of 7) (17).
Interestingly, the sweetness of xylitol is approximately on a 1:1 ratio with sugar.
Despite this, xylitol only contains 2.4 calories per gram rather than four calories like all regular carbohydrates.
- Xylitol is beneficial for dental health, and it may help to prevent plaque (18).
- Based on animal studies, intake of xylitol may improve the variety and quality of gut flora (19).
- Although xylitol contains calories and carbohydrate, it does not raise blood glucose or insulin levels. This makes it a diabetes-friendly sweetener (20).
- Similar to other sugar alcohols, xylitol may cause symptoms of gastrointestinal distress in some people (21).
- Xylitol is highly toxic (and can even be fatal) for dogs. For dog owners, therefore, it might not be the best option.
Sorbitol is only about half as sweet as sugar and contains 2.6 calories per gram.
12) Swerve Sweetener
Swerve sweetener is a popular low carb sugar substitute with the baking crowd.
This low carb sweetener uses a blend of three different ingredients; erythritol, oligosaccharides (a prebiotic fiber) and ‘natural flavors.’
As a result, it provides a consistency very similar to sugar and also fulfills its ‘ultimate sugar replacement’ slogan.
There are some tasty recipes that use Swerve here.
There is a wide range of caloric sweeteners that many people believe are superior to regular table sugar.
However, while these choices might be better, they are still sugar.
In other words; we digest them as sugar, and our body treats them like sugar, and they will raise blood sugar levels.
For this reason, they are not a good choice for tight glycemic control.
However, they are probably okay in small amounts.
13) Coconut Sugar
It’s a better substitute for sugar because it manages to have some nutritional value.
However, the minimal levels of nutrients in coconut sugar do not make it a healthy choice, and it is still high in sugar.
Coconut sugar has a glycemic index of 54 (25).
Particularly for unrefined honey, it is a source of some nutrients and polyphenols.
Despite this, it will never be a perfect choice since it is so high in sugar.
Honey’s glycemic score can be as low as 35, depending on the concentration of fructose present (26).
15) Maple Syrup
Maple syrup is another non-refined caloric sweetener, originating in Canada and the United States.
Maple syrup has a glycemic index of 54 (27).
Similar to honey, maple syrup contains small amounts of minerals and phenolic compounds.
16) Yacon Syrup
Yacon syrup contains a non-digestive form of carbohydrate known as fructooligosaccharides (FOS).
FOS is not digested, which means that not all of yacon syrup’s carbs are metabolized.
However, yacon syrup still does contain digestible carbohydrate, so it isn’t the best low carb option.
17) High-Fructose Corn Syrup
High-fructose corn syrup (HFCS) is prevalent within the food industry, and so many products use it.
However, it is ultra-processed and offers little in the way of nutrition. Further, it has a similar glycemic response to regular sugar (28).
Which Is the Best Low Carb Sweetener?
Firstly, there are several good sweetener options, and the answer to which is “best” is subjective.
However, based on the evidence, erythritol seems to have the best overall profile for a good mix of benefits, taste, and safety.
Other decent options include stevia, Swerve sweetener, monk fruit, and xylitol.
Lastly, it is worth remembering that healthy diets should emphasize whole foods.
Using low carb sweeteners from time to time can be compatible with a healthy diet.
However, we should focus on foods with the most nutrient-density.
Sweeteners provide little in the way of nutrition, and their primary health benefit is that they are better than sugar.