Which oil has a low glycemic index?

November 21, 2025 •

4 min read

The glycemic index (GI) is a tool used to measure how carbohydrates raise blood sugar levels. A common misconception is that some oils have a higher GI than others, but since all oils are pure fat and contain no carbohydrates, the short answer to which oil has a low glycemic index is that all oils have a GI of zero.

Quick Summary

While all oils technically possess a zero glycemic index, the types of healthy fats they contain can significantly impact insulin sensitivity and overall blood sugar control. Learn about the best options.

Key Points

All Oils Have a GI of Zero: Because they contain no carbohydrates, all cooking oils have a glycemic index of zero and do not directly raise blood sugar.
Fat Type is Key: The type of fat in oil, particularly monounsaturated and polyunsaturated fats, is what influences blood sugar control by improving insulin sensitivity.
Best Oils for Blood Sugar: Extra virgin olive oil, avocado oil, and canola oil are highly recommended for their beneficial fat profiles and positive effects on insulin function.
Use Cautious Moderation: Coconut oil is high in saturated fat and should be used sparingly, while refined oils high in omega-6s, like corn or soybean oil, may contribute to inflammation.
Culinary Applications Vary: High-heat cooking is best for stable oils like avocado, while delicate omega-3-rich oils like flaxseed oil are better for dressings and low-heat applications.
Portion Size Matters: All oils are high in calories, so even healthy fats should be consumed in moderation as part of a balanced diet for effective blood sugar management.

The Glycemic Index Explained

To understand why all oils have a glycemic index of zero, it's crucial to grasp what the GI measures. The GI scale classifies carbohydrate-containing foods based on how quickly and how much they raise blood sugar levels. As oils contain no carbohydrates, they do not trigger a blood sugar response in the same way sugary or starchy foods do. This makes the GI scale a non-factor for assessing oils directly.

Why Your Choice of Oil Still Matters for Blood Sugar

Despite the universal zero GI score for oils, your choice of cooking fat is critical for metabolic health, particularly for managing blood sugar. The type of fat affects your body's insulin sensitivity, which is its ability to use insulin effectively to lower blood sugar. Choosing fats high in monounsaturated fatty acids (MUFAs) and polyunsaturated fatty acids (PUFAs) can improve insulin sensitivity and support heart health, which is especially important for individuals managing diabetes. These fats can also help slow the absorption of sugars from other foods in a meal, leading to a more gradual rise in blood sugar.

Top Low-GI-Impact Oils for Cooking and Health

Extra Virgin Olive Oil (EVOO)

Widely regarded as one of the healthiest oils, EVOO is rich in MUFAs and antioxidants like polyphenols. These components have been shown to enhance insulin sensitivity and reduce inflammation. Studies have also demonstrated that EVOO can help lower the glycemic impact of a meal when consumed with carbohydrate-rich foods.

Avocado Oil

Similar to olive oil, avocado oil is packed with heart-healthy MUFAs. It is also a good source of vitamin E and antioxidants. This nutrient profile contributes to improved insulin sensitivity and anti-inflammatory effects. Its mild flavor and high smoke point make it a versatile choice for various cooking methods.

Canola Oil

Canola oil provides a balanced mix of MUFAs and PUFAs, including a favorable ratio of omega-6 to omega-3 fatty acids. Research suggests that it can help improve insulin sensitivity and lower LDL (bad) cholesterol, benefiting those with diabetes. Its neutral taste and high heat tolerance make it an excellent everyday cooking oil.

Flaxseed Oil

Valued for its high content of omega-3 fatty acid (alpha-linolenic acid), flaxseed oil is a potent anti-inflammatory agent. Omega-3s have been shown to improve insulin sensitivity. However, due to its low smoke point, flaxseed oil is best used for salad dressings or drizzling over dishes rather than high-heat cooking.

Algae Oil

An emerging option, algae oil is a sustainable and nutrient-dense source of healthy fat, containing a high percentage of oleic acid (a MUFA). It has a very high smoke point, making it suitable for all types of cooking, and helps lower bad cholesterol while raising good cholesterol.

Oils to Use with Caution or in Moderation

While coconut oil technically has a zero GI, its high saturated fat content should be consumed in moderation. Some refined oils, especially those high in omega-6 fatty acids, can be pro-inflammatory when not balanced with sufficient omega-3s, potentially contributing to insulin resistance over time. These include refined sunflower oil, corn oil, and soybean oil.

Low-GI Oil Comparison Table


Feature	Extra Virgin Olive Oil	Avocado Oil	Canola Oil	Flaxseed Oil
Fat Profile	High MUFA	High MUFA	Balanced MUFA/PUFA	High Omega-3 (PUFA)
GI	0	0	0	0
Insulin Sensitivity	Excellent	Excellent	Good	Excellent
Anti-Inflammatory	Yes (Polyphenols)	Yes (Vitamin E)	Yes	Strong (Omega-3)
Smoke Point	Medium	High	High	Very Low
Best Use	Dressings, sautéing	High-heat cooking, dressings	Everyday cooking	Dressings, dips, low-heat

Healthy Ways to Incorporate Low-GI-Impact Oils

Using the right cooking fats is a simple yet effective strategy for managing blood sugar and supporting overall health. Here are some healthy culinary uses for these oils:

Salad Dressings: Create flavorful, homemade dressings with extra virgin olive oil or flaxseed oil. Combining with vinegar and herbs provides a delicious, low-carb topping.
Sautéing and Roasting: Use avocado or canola oil for sautéing vegetables, chicken, or fish. Their high smoke points prevent the oil from breaking down into less healthy compounds.
Dipping and Finishing: Drizzle high-quality extra virgin olive oil over bread, soups, or steamed vegetables for added flavor and nutrients.
Baking: Replace solid fats like butter with canola or algae oil in baking recipes to incorporate healthy fats.
Smoothies: Add a tablespoon of flaxseed oil to smoothies for an omega-3 boost without altering the taste significantly.

Conclusion: Making the Right Choice

While the answer to which oil has a low glycemic index is technically all of them, the health impact of your oil choice is anything but zero. The focus should shift from the non-existent GI score to the fat profile and processing method of the oil. Prioritizing oils rich in monounsaturated and polyunsaturated fats, like extra virgin olive oil, avocado oil, and canola oil, can significantly improve insulin sensitivity, reduce inflammation, and support heart health. Integrating these fats into a balanced diet, paired with portion control, is a proactive step toward effective blood sugar management. Always consult with a healthcare professional or dietitian to align your dietary choices with your specific health needs.

For more detailed information on glycemic index and diet, you can refer to authoritative sources like the MedlinePlus guide on the topic.

Frequently Asked Questions

The glycemic index is a system that ranks carbohydrate-containing foods based on how quickly they raise blood glucose levels after consumption. It does not apply to foods without carbohydrates, such as oils.

Yes, olive oil, like all other oils, has a glycemic index of zero because it contains no carbohydrates. It is also beneficial for blood sugar management due to its high content of monounsaturated fats.

Yes, coconut oil has a GI of 0. However, because it is high in saturated fat, it should be used in moderation, especially when managing diabetes and heart health.

Sunflower oil has a low glycemic index of zero and does not directly raise blood sugar. However, the type of sunflower oil matters; high-oleic versions are healthier than refined versions high in inflammatory omega-6s.

The fats in oil can improve insulin sensitivity, which helps your body better regulate blood sugar. Healthy fats can also slow down the digestion of a meal, leading to a more stable post-meal blood sugar response.

Extra virgin olive oil, avocado oil, and canola oil are among the healthiest for daily cooking due to their high monounsaturated fat content, which supports insulin sensitivity and heart health.

Refined oils high in omega-6 fatty acids, such as corn or soybean oil, may promote chronic inflammation over time when consumed in excess and without balance from omega-3s, which is a concern for people with diabetes. Opting for less refined, healthier options is generally recommended.