What is the lowest GI sweetener?

October 23, 2025 •

4 min read

According to numerous clinical studies, including those reviewed by the FDA, several natural sweeteners have a glycemic index (GI) of zero. This means they do not raise blood sugar levels, making them the lowest GI sweetener options available. While many low-GI sweeteners exist, some, like stevia, monk fruit, and allulose, have negligible or no impact on blood glucose at all.

Quick Summary

Several natural sugar alternatives, including stevia, monk fruit, and erythritol, possess a zero or near-zero glycemic index, making them the lowest GI sweetener choices for maintaining stable blood sugar and supporting a healthy diet.

Key Points

Lowest GI Sweeteners: Several sweeteners, including monk fruit, stevia, erythritol, and allulose, have a glycemic index of zero.
Monk Fruit: Derived from a fruit, it offers potent sweetness with a GI of zero and no calories or carbs.
Stevia: A plant-based sweetener with a GI of zero, but some people notice a distinct aftertaste.
Erythritol: A sugar alcohol with a zero GI and good tolerance at moderate doses, suitable for baking.
Allulose: A rare sugar with a zero GI that performs very similarly to table sugar in recipes.
Baking and Cooking: Allulose is best for replicating sugar's behavior, while erythritol is a good bulking agent.
Taste: Monk fruit has a clean taste, while stevia can have a bitter aftertaste; erythritol has a cooling effect.
Diabetic Friendly: These zero-GI sweeteners are excellent alternatives for people managing blood sugar.

Exploring Sweeteners with a Zero Glycemic Index

The glycemic index (GI) is a numerical ranking system that measures how quickly carbohydrate-containing foods raise blood glucose levels. A lower GI is generally preferred, especially for individuals managing diabetes or seeking better blood sugar control and weight management. Foods with a GI of 55 or less are considered low, but a select group of sweeteners achieves an impressive GI score of zero. These non-nutritive sweeteners provide sweetness without contributing to the overall glycemic load of a meal.

Monk Fruit

Monk fruit, also known as Luo Han Guo, is a small, melon-like fruit native to Southeast Asia. Its sweetness comes from compounds called mogrosides, which are potent antioxidants. The extraction of these mogrosides creates a zero-calorie, zero-carbohydrate sweetener with a GI of zero. It is exceptionally sweeter than table sugar, so only a small amount is needed.

Benefits of Monk Fruit:

Zero calories and zero carbs.
No impact on blood sugar levels.
Widely recognized as safe (GRAS) by the FDA.
Offers antioxidant properties.

Stevia

Stevia is a natural, calorie-free sweetener derived from the leaves of the Stevia rebaudiana plant. Its sweetness comes from steviol glycosides and, like monk fruit, it has a glycemic index of zero. However, some individuals notice a slight aftertaste, which is why pure stevia extract is often preferred over products with added fillers like erythritol.

Benefits of Stevia:

Zero calories and zero carbs.
GI of 0, making it safe for those managing blood sugar.
Long history of use in South America.
Pure versions do not have health risks associated with certain fillers.

Erythritol

Erythritol is a sugar alcohol found naturally in some fruits, but it is commercially produced by fermenting cornstarch. It has a glycemic index of zero and is well-tolerated by most people, unlike some other sugar alcohols that can cause digestive issues. Erythritol is about 70% as sweet as sugar and has a slight cooling effect in the mouth.

Benefits of Erythritol:

Zero GI and minimal calories (0.2 kcal/g).
Easily absorbed and largely excreted unchanged by the body, minimizing digestive upset at moderate doses.
Does not cause tooth decay.
Bakes well in recipes requiring bulk.

Allulose

Allulose is a rare sugar found in small amounts in figs, raisins, and jackfruit. It is about 70% as sweet as table sugar but has almost no calories and a glycemic index of zero. Studies have shown that allulose not only has a zero GI but may also help flatten blood sugar spikes when consumed with other sugary foods.

Benefits of Allulose:

GI of 0.
Tastes and performs very similarly to regular sugar in baking.
May improve insulin sensitivity and support heart and liver health.
Does not contribute to dental cavities.

Comparison of Low GI Sweeteners

This table provides a quick reference for the most popular zero or very low GI sweeteners, highlighting their key differences.


Feature	Monk Fruit	Stevia	Erythritol	Allulose
Glycemic Index (GI)	0	0	0	0
Calories (per gram)	0	0	~0.2	~0.4
Sweetness	150-250x sweeter than sugar	200-300x sweeter than sugar	70% as sweet as sugar	70% as sweet as sugar
Taste Profile	Clean, no aftertaste in pure form	Some bitterness or metallic aftertaste	Slight cooling effect	Clean, very similar to sugar
Baking Use	Requires adjustment for volume	Requires adjustment for volume; can have an aftertaste	Bulking agent, similar to sugar	Excellent, mimics sugar's properties
Digestive Issues	Rare	Some report upset stomach	Well-tolerated in moderate amounts	Rare; potential for mild discomfort with very large doses

Natural vs. Artificial Sweeteners

While natural zero-GI sweeteners like stevia and monk fruit are derived from plants, many zero-GI options are artificial. Artificial sweeteners such as aspartame and sucralose also have a GI of zero. However, some research suggests artificial sweeteners may negatively impact gut microbiota and potentially lead to metabolic issues, though more studies are needed. Ultimately, many health-conscious individuals prefer natural sources like stevia, monk fruit, or allulose over synthetic alternatives.

Choosing the Best Zero-GI Sweetener for You

Selecting the best zero-GI sweetener depends largely on personal preference, intended use, and potential health considerations.

For beverages and general tabletop use: Both monk fruit and stevia are excellent, zero-calorie options with a GI of 0. Their concentration means you only need a small amount, but taste preference (minimal aftertaste with monk fruit versus potential bitter notes with stevia) is the deciding factor.
For baking: Allulose is the standout performer for baked goods, as it behaves most like sugar in both taste and texture. Erythritol also works well as a bulking agent, though it may not brown in the same way as sugar.
For those with digestive sensitivities: Erythritol is generally well-tolerated at moderate levels compared to other sugar alcohols like xylitol, which has a low GI of 7 but is more likely to cause digestive upset. Allulose is also gentle on the digestive system for most people.
For natural alternatives: Stevia, monk fruit, and allulose are all excellent choices. They are derived from natural sources and have a minimal or zero glycemic impact.

Conclusion

In summary, the lowest GI sweeteners are a group of zero-glycemic options that include stevia, monk fruit, erythritol, and allulose. Each offers a path to enjoying sweetness without affecting blood sugar levels, making them excellent choices for those managing diabetes or following a low-carb diet. While all share a negligible glycemic impact, they differ in taste, baking performance, and potential for minor side effects. Your choice will depend on your specific culinary needs and taste preferences. As with any dietary change, moderation is key, and it's always wise to monitor your body's response.

is a resource providing more information about low-GI sweeteners and healthy eating.

Final Recommendations

For a clean, natural taste in drinks: Monk fruit or pure stevia extract are zero-GI options that won't raise blood sugar.
For replicating sugar in baking: Allulose is the closest match in texture and flavor, with a zero GI.
For an all-purpose, zero-calorie bulk sweetener: Erythritol is a reliable and well-tolerated choice with a zero GI.

Frequently Asked Questions

Both monk fruit and stevia have a glycemic index of zero, no calories, and are significantly sweeter than sugar. The main difference is taste; monk fruit generally has a cleaner taste with less aftertaste, while stevia can have a slightly bitter or metallic flavor for some individuals.

Yes, allulose is safe for people with diabetes. It has a glycemic index of zero and does not raise blood sugar or insulin levels. Some studies even suggest it can help flatten post-meal glucose spikes.

Erythritol can be used in baking and is a good bulking agent. It is only about 70% as sweet as sugar, so recipes may need adjustment. It also has a distinct cooling sensation in the mouth.

Not necessarily. While sweeteners like stevia and monk fruit are derived from plants, some 'natural' sweeteners like agave nectar have a low GI but are very high in fructose, which can pose health risks in excessive amounts. It is important to consider the overall impact and not just the GI score.

Zero-GI sweeteners are generally well-tolerated. However, some sugar alcohols like erythritol can cause digestive upset if consumed in large quantities, though it is better tolerated than others. Stevia can also cause mild digestive issues in some people.

Artificial sweeteners like sucralose and aspartame also have a zero GI but are chemically synthesized. Some research suggests potential negative effects on gut health, while natural options like stevia and monk fruit are often preferred by those seeking less processed alternatives.

Other sweeteners have low, but not zero, GI scores. For example, xylitol has a GI of 7, agave nectar is around 10-27 (but high in fructose), and coconut sugar is around 35. These are still lower than table sugar (GI 60-70), but not zero.