Does Teff Have a Low Glycemic Index? Understanding its Effects on Blood Sugar

December 6, 2025 •

3 min read

Multiple studies on teff's glycemic index (GI) have shown that its value is not fixed, but varies significantly depending on how the grain is prepared. This nutritional ambiguity is crucial for anyone monitoring their blood sugar, as the ancient grain's impact can be very different based on the final product.

Quick Summary

The glycemic index of teff is variable, ranging from low for fermented products like injera to high for processed items like porridge, influenced by factors like fiber and preparation methods.

Key Points

GI Varies by Preparation: Teff's glycemic index is not uniform, ranging from low in fermented forms like injera to high in processed products like porridge.
Injera is Low GI: Fermented teff injera typically has a low glycemic index of around 36, making it an excellent choice for blood sugar control.
Whole Grain is Moderate GI: Cooked whole grain teff has a moderate GI of about 57, offering slower glucose absorption than many common refined grains.
Fiber is a Key Factor: Teff's high fiber content, including resistant starch, is a primary reason for its beneficial effect on glycemic response, promoting slow and steady glucose release.
Nutrient-Dense Choice: Beyond its glycemic properties, teff is a nutritional powerhouse, providing high-quality protein, essential amino acids, and vital minerals like iron and calcium.

What is the Glycemic Index (GI)?

The Glycemic Index is a system that ranks carbohydrate-containing foods based on how quickly they raise blood sugar levels after eating. Foods are categorized into three groups:

Low GI: 55 or less
Moderate GI: 56–69
High GI: 70 or higher

For individuals with diabetes or those looking to maintain stable energy levels, choosing foods with a lower GI is often recommended to prevent rapid blood sugar spikes.

The Varying Glycemic Index of Teff

Unlike many grains with a single GI value, teff's glycemic response is highly dependent on how it is processed and consumed. This is a critical distinction for dietary planning.

Teff Injera (Fermented Teff)

Injera, the traditional Ethiopian fermented flatbread made from teff, consistently shows a low GI. A study published in Diabetes, Metabolic Syndrome and Obesity found the GI of teff injera to be approximately 36, which is remarkably low and ideal for glycemic control. Fermentation plays a key role in lowering the GI by altering the starch structure and increasing resistant starch content.

Whole Grain Teff (Cooked)

When cooked and consumed as a whole grain, similar to how rice or quinoa is prepared, teff falls into the moderate GI category. A report from Foodwatch notes that cooked whole grain teff has a GI of around 57. Its high fiber content, including resistant starch, contributes to this more moderate glycemic response.

Teff Porridge and Bread (Processed Teff)

Processing teff into other products can significantly increase its GI. Teff flour bread has been shown to have a higher GI, comparable to some wheat products. Similarly, teff porridge can have a very high GI due to the cooking process breaking down starches, leading to faster digestion and absorption.

Why Teff Affects Blood Sugar Differently

Several nutritional properties contribute to teff's unique glycemic profile, particularly in its whole grain and fermented forms.

High Fiber Content

Teff is rich in dietary fiber, which slows down digestion and the absorption of glucose into the bloodstream. This results in a slower, more gradual rise in blood sugar, preventing the spikes associated with high-GI foods.

Resistant Starch

This ancient grain contains a significant amount of resistant starch, a type of carbohydrate that passes through the small intestine undigested and ferments in the large intestine. This process feeds beneficial gut bacteria and has been shown to help stabilize blood sugar levels. Fermentation, as with injera, enhances the resistant starch content.

Complete Protein Profile

With a high protein content that includes all nine essential amino acids, teff promotes satiety and helps to moderate blood sugar response. The protein helps slow digestion and contributes to better glycemic control overall.

Comparison of Glycemic Impact: Teff vs. Other Grains

To put teff's GI into context, here is how different preparations compare to other common whole grains. It is important to note that specific GI values can vary slightly based on testing methods and variety.


Food Item (Preparation)	Glycemic Index (GI)	Glycemic Category	Key Factors	Notes
Teff Injera (Fermented)	~36	Low	High resistant starch from fermentation	Traditional Ethiopian flatbread
Teff (Whole Grain) (Cooked)	~57	Moderate	High fiber, resistant starch, and protein	Cooked like rice or quinoa
Quinoa (Cooked)	~53	Low	Good protein and fiber content	A low GI alternative to rice or oats
Brown Rice (Cooked)	~68	Moderate	Fiber is concentrated in the bran layer	A whole grain with a slower absorption rate
White Rice (Cooked)	~73	High	Refined grain with minimal fiber	Rapidly digested, causing blood sugar spikes

Conclusion: Making the Right Choice for Your Diet

While the answer to "does teff have a low glycemic index?" is complex, the overall nutritional profile and potential for managing blood sugar are clear. For optimal glycemic control, especially for those with diabetes, consuming teff in its fermented form (injera) or as a minimally processed whole grain is the best approach. Processed forms like breads and porridges can have a higher GI and should be consumed with more caution, particularly by those sensitive to blood sugar fluctuations. As a versatile, gluten-free grain rich in fiber and protein, teff offers a healthy and flavorful alternative for a wide range of dietary needs.

For a deeper dive into the nutritional values of teff for managing diabetes, consult published research such as the review article Nutritional Values of Teff (Eragrostis tef) in Diabetic Patients available through the National Institutes of Health.

Frequently Asked Questions

Yes, teff is an excellent grain for people with diabetes, especially when consumed as fermented injera or a whole grain, due to its low to moderate glycemic index and high fiber content, which aid in blood sugar control.

No, teff bread typically has a high glycemic index (around 74), which is significantly higher than fermented teff injera and cooked whole grain teff.

Cooked whole grain teff has a moderate GI (around 57), which is similar to quinoa's low GI (around 53). However, fermented teff injera has a much lower GI than quinoa.

The GI changes because processing methods like fermentation or cooking break down the grain's starches differently. Fermentation increases resistant starch, lowering the GI, while extensive cooking, such as in porridge, makes starches more readily available, increasing the GI.

Yes, teff is naturally gluten-free, making it a safe and nutritious option for individuals with celiac disease or gluten sensitivities.

Minimally processed forms like fermented injera or cooked whole grain teff are unlikely to cause significant blood sugar spikes due to their fiber and protein content. However, highly processed forms like teff porridge or some breads can cause a rapid rise in blood sugar.

Resistant starch is a type of fiber in teff that resists digestion in the small intestine. It ferments in the large intestine, which helps to stabilize blood sugar levels and contributes to a lower GI.