Which Sugar Has the Lowest Glycemic Index? A Comprehensive Guide to Sweeteners

October 20, 2025 •

4 min read

The glycemic index (GI) is a measurement scale ranking carbohydrates from 0 to 100 based on their impact on blood glucose levels. A GI score below 55 is considered low, while zero-calorie sweeteners like stevia and monk fruit are confirmed to have a GI of 0. Choosing the right sweeteners can be key for managing blood sugar, especially when exploring Which sugar has the lowest glycemic index?

Quick Summary

Several sweeteners, including stevia, monk fruit, and erythritol, offer a glycemic index of zero, while allulose has a GI of one, making them ideal for stable blood sugar. The low GI of sweeteners depends on their composition, with fructose having a lower GI than glucose-rich options. Considerations for use extend beyond GI to include overall diet and serving size.

Key Points

Zero-GI Sweeteners: Stevia, monk fruit, and erythritol have a glycemic index of zero and do not affect blood sugar levels.
Allulose is Nearly Zero: This rare sugar has a GI of 1 and minimal impact on blood glucose.
Natural Sugars are Not Zero-GI: Sweeteners like agave nectar and coconut sugar have lower GIs than table sugar but still raise blood sugar and should be consumed in moderation.
Consider Glycemic Load: The impact of a food depends on both its GI and the portion size, known as the glycemic load.
Read Labels and Consult Experts: Some sweeteners can be blended or have health considerations; always read product labels and consult a healthcare provider for specific dietary needs.
Metabolic Differences Matter: Fructose, despite its low GI, is metabolized differently and can have negative effects on metabolic health if overconsumed.

Understanding the Glycemic Index

To understand which sweeteners are best for managing blood sugar, it is crucial to first grasp the concept of the glycemic index (GI). The GI is a rating system for carbohydrate-containing foods based on how quickly and significantly they raise blood glucose levels after consumption. Foods are ranked on a scale from 0 to 100, with pure glucose serving as the reference food with a GI of 100.

GI scores are categorized as:

High GI: 70 or higher, causing a rapid increase in blood sugar.
Medium GI: 56–69, causing a moderate increase.
Low GI: 55 or lower, resulting in a slow and gradual rise in blood sugar.

For those monitoring their blood sugar, such as individuals with diabetes or those following a low-carbohydrate diet, opting for low or zero-GI sweeteners can be a critical strategy. Low-GI foods are associated with improved blood glucose control, increased satiety, and better weight management.

Zero-Glycemic Sweeteners: The Lowest GI Choices

For anyone seeking a sweetener with the absolute lowest GI, the answer lies in alternatives that have a score of zero. These options provide sweetness without any caloric load or effect on blood sugar.

Stevia: Derived from the leaves of the Stevia rebaudiana plant, stevia is a natural, calorie-free sweetener with a GI of zero. It is significantly sweeter than table sugar, so only a small amount is needed. Some individuals may experience a slightly bitter aftertaste.
Monk Fruit: Extracted from the fruit of the Siraitia grosvenorii plant, monk fruit is another natural, zero-calorie sweetener with a GI of zero. It contains compounds called mogrosides that provide intense sweetness without affecting blood sugar. Monk fruit is known for having no aftertaste.
Erythritol: A sugar alcohol produced by fermenting grains, erythritol is a calorie-free sweetener with a GI of zero. It is absorbed by the body but not metabolized for energy, so it does not affect blood sugar or insulin levels. Due to its unique digestive process, large amounts may cause gastrointestinal discomfort in some individuals.

Other Low-GI Sugar Alternatives

While not zero, several other sweeteners rank very low on the glycemic index, making them viable choices for those looking to minimize blood sugar spikes.

Allulose: This is a naturally occurring rare sugar found in small amounts in foods like figs and raisins. Allulose has a GI of just 1 and contains very few calories. Studies suggest it may even help lower post-meal blood glucose levels.
Xylitol: A sugar alcohol derived from corn or birch bark, xylitol has a GI of about 7-13. While it does contain some carbohydrates and calories, its slow absorption rate results in a minimal blood sugar impact.
Fructose: Found naturally in fruits and vegetables, pure fructose has a GI of 15-23, lower than table sugar because it is metabolized differently. However, consuming excessive fructose can be harmful to liver health and metabolic function, so it should be used with caution.
Agave Nectar: A sweetener extracted from the agave plant, its GI is reported to be between 11 and 28. Agave is high in fructose, and while this contributes to its low GI, it carries the same metabolic concerns as pure fructose, especially regarding liver health.

Comparison of Sweeteners and their Glycemic Impact


Sweetener	Type	Glycemic Index (GI)	Calories	Notes
Stevia	Natural	0	0	Derived from a plant leaf; very sweet, no effect on blood sugar.
Monk Fruit	Natural	0	0	Extracted from monk fruit; no calories, no blood sugar impact.
Erythritol	Sugar Alcohol	0	0.2/g	Fermented sugar alcohol; no blood sugar impact, can cause digestive upset in large amounts.
Allulose	Rare Sugar	1	Low	Found naturally in some fruits; low calories, minimal blood sugar effect.
Fructose	Simple Sugar	15–23	4/g	Found in fruits; lower GI but can cause metabolic issues if consumed in excess.
Agave Nectar	Natural	11–28	High	High in fructose; similar health concerns to pure fructose.
Coconut Sugar	Natural	35–54	High	Lower GI than table sugar, but contains similar calories.
Sucrose (Table Sugar)	Simple Sugar	65-68	High	A moderate to high GI sweetener.

Beyond the GI: Considerations for a Healthy Diet

While the GI is a valuable tool, it is not the only factor to consider. The overall glycemic load (GL) of a meal—which takes into account both the GI and the serving size—is equally important. A small amount of a high-GI sweetener might have less impact than a large amount of a low-GI one. Additionally, the preparation method of a food and what it is eaten with can affect its GI. Adding fat, protein, or fiber can slow down digestion and lower the overall glycemic response.

It is also essential to consider potential health risks. For example, some studies have shown an association between high consumption of the sugar alcohol erythritol and an increased risk of stroke or heart attack. Consumers should read labels carefully, as many products may blend sweeteners or include other additives. For individuals with specific health conditions, such as diabetes, consulting a healthcare professional is always recommended.

Conclusion: Making Informed Sweetener Choices

In the quest for sweeteners that have the lowest glycemic index, stevia, monk fruit, and erythritol stand out with a GI of zero, making them excellent choices for those focused on managing blood glucose levels. Allulose, with a GI of 1, is another strong contender. While natural sugars like fructose, agave nectar, and coconut sugar have lower GIs than table sugar, they are not zero and carry their own metabolic considerations, especially concerning fructose's impact on liver health. Ultimately, a balanced approach involves considering the full glycemic impact of your diet, portion sizes, and overall health goals. Opting for zero or low-GI sweeteners in moderation, combined with a healthy eating pattern, offers a path to enjoying sweetness without significant blood sugar fluctuations. For more on dietary glycemic load, you can explore research from the Linus Pauling Institute.

Frequently Asked Questions

The glycemic index is a system that ranks carbohydrate-containing foods on a scale from 0 to 100 based on how quickly they raise blood glucose levels after consumption.

For individuals managing diabetes, low GI sweeteners are a good choice because they cause a slower and more gradual rise in blood sugar, helping to improve blood glucose control and prevent spikes.

Table sugar (sucrose) has a GI of approximately 65-68, placing it in the moderate to high category.

Coconut sugar has a moderately low GI, typically reported between 35 and 54, which is lower than table sugar, but it still contains the same calories and carbohydrates.

Honey has a GI that varies depending on the type, but it is generally in the medium GI range (around 55-62), making stevia a better choice for diabetics.

Sugar alcohols, such as erythritol and xylitol, are carbohydrates that taste sweet but are not completely absorbed by the body. They typically have a low GI and minimal impact on blood sugar, with erythritol having a GI of 0 and xylitol having a GI of 7-13.

No, while low GI sweeteners can be beneficial, factors like overall glycemic load, serving size, and potential side effects should be considered. Even with low GI options, moderation is key.