Are artificial sweeteners allowed when fasting?

Studies have shown that artificial sweeteners may confuse the body into thinking the calories are not having an effect on the body, which can lead to weight gain. A recent study published in the Journal of General Internal Medicine found that diet soda drinkers were more likely to have a higher body mass index (BMI) compared to those who drank unsweetened beverages. This trend translated to worse overall health outcomes, including higher levels of inflammation, a higher incidence of heart disease, and higher rates of diabetes in the study participants.

If you want to fast, then you should follow the Islamic (fard) sunnah (lit.  “recommended”) practice of abstaining from eating and drinking from dawn to dusk.

Fasting is becoming more popular and a more common way to balance our diet. However, there are some that think that artificial sweeteners are not allowed during a fast, which could be problematic since it would leave you with a craving for sugar.


Intermittent fasting, for example, raises a slew of questions:

  • Is it OK to use artificial sweeteners during Lent?
  • Is there a link between fat and autophagy during fasting?
  • On Shrove Tuesday, a 500-calorie meal?

Dr. Jason Fung is a world-renowned specialist in fasting for weight reduction and diabetes management. His responses to these and other questions are as follows:

Is it OK to use artificial sweeteners during Lent?

Hello, I have a sweet craving and find it difficult to consume black coffee or tea. Does stevia or xylitol put you at danger of starvation?


Artificial sweeteners may cause the secretion of insulin to be stimulated. Fasting with sweets is an option; if it works for you, keep doing it.

Jason Fung, M.D.

Is there a link between fat and autophagy during fasting?

Hello, Jason. Does coconut oil, which is 100 percent fat and leaves virtually little residue, have an effect on autophagy if it also keeps ketone levels high?


Probably not, despite the lack of research. Proteins typically stop autophagy from working.

Jason Fung, M.D.

Fasting days with 500-calorie meals?

On fasting days, several fasting diets (such as the every other day diet and the 5:2 diet) suggest consuming between 500 and 600 calories. Why? This, in my view, may cause an insulin surge and a short break in fasting. Isn’t it preferable to abstain from eating during Lent? Is there a physiological basis for the authors’ recommendation, or is it simply to promote participant compliance? Jeff, thank you so much.

Because they think that a day of total fasting (0 calories) is too tough for most individuals, the authors suggest this. I don’t agree. However, you obtain excellent results with this tweak, and I don’t mind these settings.

Jason Fung, M.D.

Additional information

Beginner’s Guide to Intermittent Fasting

Other inquiries and responses

Dr. Fung’s previous question and answer sessions include:

There will be a lot of questions and answers after that:

Intermittent fasting questions and answers

Additional information

To learn a lot, read Dr. Jason Fung’s outstanding new book The Obesity Code:


The idea of fasting is often a controversial topic, and for good reason, since most methods fail to stick with the traditional reason behind why so many religions practice it: to cleanse the body from its impurities. When it comes to fasting, there are two categories of food that the body tends to crave: carbohydrates and water. The first category, carbohydrates, consists of foods we need for energy and nutrients, such as fruits, vegetables, beans, milk, bread and grains. The second category is water, which is essential for the body to function properly.. Read more about does xylitol break a fast and let us know what you think.

Frequently Asked Questions

Can I use artificial sweeteners while fasting?

Artificial sweeteners are not allowed during fasting.

Does coffee with sweetener break a fast?

No, coffee with sweetener does not break a fast.

Can I drink tea with stevia while fasting?

You can drink tea with stevia while fasting, but you should not consume any other sweeteners or sugar.

Related Tags

This article broadly covered the following related topics:

  • intermittent fasting and artificial sweeteners
  • does erythritol break a fast
  • stevia intermittent fasting
  • is stevia ok on intermittent fasting
  • will stevia break my fast

Una is a food website blogger motivated by her love of cooking and her passion for exploring the connection between food and culture. With an enthusiasm for creating recipes that are simple, seasonal, and international, she has been able to connect with people around the world through her website. Una's recipes are inspired by her travels across Mexico, Portugal, India, Thailand, Australia and China. In each of these countries she has experienced local dishes while learning about the culture as well as gaining insight into how food can be used as a bridge between different cultures. Her recipes are often creative combinations of traditional ingredients from various different cuisines blended together to create something new.