Is Isomalt Keto Friendly?

Answer: Isomalt's low glycemic index means it won't spike your blood sugar or interfere with your ketosis, making it keto-compatible. Watch out for its uncomfortable side effects around digestion.

Keto Meter: 3

Isomalt is a sugar substitute that often appears in sugar-free candies and snacks. It's keto-friendly in that it has a very low glycemic index, which means that it won't spike your blood sugar and interfere with your ketosis.


Safety is a concern with any artificial sweetener. There's fierce debate over the safety of many sugar substitutes. Eliminating sugar is great, but nobody wants a replacement that's going to cause health complications.

More than 80 countries allow isomalt in food products, including the US, the EU, Japan, and Australia.

The World Health Organization's Joint Expert Committee on Food Additives (JECFA) evaluated isomalt in 1985 and placed it into its safest food category.

Gastrointestinal issues

Some studies have found isomalt is associated with gastrointestinal distress, such as flatulence and diarrhea. The digestive issues seem to only occur when you eat more than 20 g of isomalt in a day, and only ~25% experience this, but it's definitely worth caution.

If you find that isomalt doesn't upset your stomach, you can stick with it as a keto-safe replacement for sugary foods. But if you feel an upset tummy after eating foods with isomalt, it's time to find a new sweetener.


For a more natural alternative, consider stevia or monk fruit. Both are all-natural and have nearly zero effect on blood sugar.

Other popular keto-friendly sweeteners include erythritol and xylitol. They're sugar alcohols, which humans can't digest, so you get the sweetness without the carbs.

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