Intermittent fasting is one of the most popular diet trends of the last few years.

There are several styles of intermittent fasting, each with its own rules and protocols. These differences can sometimes make the practice confusing for people who are just getting started.

Stevia is a popular sugar substitute that’s often used to reduce sugar intake or promote more balanced blood sugar levels.

Many people wonder whether it’s OK to consume stevia while they’re fasting, or if it should be saved for times when you’re allowed to eat.

This article reviews how stevia affects fasting and whether it’s OK to consume it during a fasting window.

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Stevia is a type of natural sweetener derived from the plant Stevia rebaudiana. It tastes up to 300 times sweeter than regular sugar but contains no calories or carbs (1).

Weight loss and improved blood sugar regulation are some of the most popular reasons people choose to adopt an intermittent fasting practice.

Early research indicates that stevia does not significantly raise insulin or blood sugar levels and — because it doesn’t contain calories — it may help people who are trying to reduce their calorie intake to lose weight (2, 3, 4).

Autophagy is a natural bodily process that recycles damaged components within your cells. Some research suggests that short-term fasting may be a good way to stimulate your body’s autophagy processes, although research in humans is limited (5).

Some people adopt intermittent fasting in hopes of obtaining health benefits associated with autophagy, such as increased energy levels and improved brain health (5).

Although no research has focused specifically on stevia’s effect on autophagy in humans, some experts assert that a moderate intake of stevia is unlikely to significantly affect that cellular process (6).

How much is too much?

Using stevia in moderation is unlikely to break your fast or reduce any of the potential benefits you’re trying to obtain from fasting.

However, it’s possible to have too much of a good thing.

The Food and Drug Administration (FDA) set the acceptable daily limit of stevia extract ingestion at 1.8 mg per pound (4 mg per kg) of body weight. For someone who weighs 150 pounds (68 kg), that equates to about 272 mg per day (7).

Serving sizes may vary depending on the brand, but a typical serving of pure liquid stevia extract is about 5–7 drops, which contains approximately 20–50 mg of stevia.

For safety purposes, a 150-pound (68-kg) person should limit their intake to no more than five 50-mg servings of liquid stevia per day. This equates to about 25–60 drops depending on the strength of your product.

Since the potency can vary between brands, check the product label or contact the manufacturer directly to find out how much stevia the drops provide per serving.


Stevia doesn’t contain any calories and is unlikely to cause significant metabolic changes. Thus, a moderate intake of stevia is likely alright during a fast.

Stevia is commercially available in a variety of forms, many of which have fillers and added ingredients that may be inappropriate to consume during your fast.

For instance, some stevia products contain small amounts of dextrose or maltodextrin, both of which are carbs and contain calories.

To avoid accidentally breaking your fast with these added ingredients, many people prefer sticking to stevia products made exclusively with pure stevia extract.

If you’re unsure whether your favorite stevia product only contains pure stevia, you can simply check the ingredient list on the package to verify.


Some stevia-based products include carb-containing additives. To err on the side of caution, you may want to opt for stevia products that only contain pure stevia extract while you’re fasting.

Intermittent fasting is a popular dieting strategy that’s used for a variety of health benefits, such as weight loss and improved blood sugar control.

Stevia is a natural type of sugar substitute that doesn’t contain any calories or carbs. Early research indicates that the moderate use of stevia during a fast is unlikely to significantly impede any of the potential benefits of fasting.

However, certain types of stevia products contain small amounts of carb-containing ingredients that could potentially break your fast if you consume too much.

Thus, if you plan on consuming stevia during a fast, you may want to opt for brands that are made only with pure stevia extract.