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Home arrow Nutrition arrow Intermittent Fasting arrow Does Metamucil Break a Fast? A Look at the Fiber Supplement

Does Metamucil Break a Fast? A Look at the Fiber Supplement

Written by Edibel Quintero, RD
Fact checked by Rosmy Barrios, MD
Last update: October 22, 2023
3 min read 1454 Views 0 Comments
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Fiber supplements can help boost your digestive health and keep your bowel movements in check. Some people experience digestive issues on their intermittent fasting journey, but is it safe to take your usual supplement in the fasting window? Keep reading to find out if Metamucil will break your fast.

Does Metamucil Break a Fast_ A Look at the Fiber Supplement

Sometimes your digestive health needs a little pick-me-up.

Digestive issues, such as constipation or diarrhea, can cause a lot of problems in daily life. Irregular bowel movements can leave you feeling bloated, gassy, and generally uncomfortable. Often, these troubles can result from a lack of dietary fiber in the diet.

To increase your fiber intake, you might consider taking fiber supplements. Metamucil is a popular fiber supplement brand that provides constipation relief and other health benefits. It sounds like a possible solution to support an ordinary diet, but what if you’re practicing intermittent fasting?

In this article, our expert answers if Metamucil will break your fast or if it is safe to use during your fasting window.

Does Metamucil Break a Fast?

Yes, taking Metamucil during the fasting window will break a fast. The star ingredient and main component in Metamucil is psyllium husk – a natural source of soluble fiber. While psyllium husk fiber alone will not end the benefits of intermittent fasting, the other ingredients in Metamucil will. This fiber supplement contains artificial ingredients, including maltodextrin, aspartame, or other carbohydrates.

Maltodextrin is a class of carbohydrates. It is a highly processed white powder made from corn, potato starch, rice, or wheat. This artificial sweetener is commonly used as a food additive to thicken and increase the volume of processed foods. This carb has a high glycemic index and is quickly absorbed into the bloodstream, spiking blood sugar levels and breaking the fast.

What Is Metamucil?

Metamucil is a fiber supplement created to help people boost their fiber intake and support a healthy digestive system. The creators also claim that Metamucil can help regulate blood sugar levels, improve heart health by reducing cholesterol, and support appetite control. Although Metamucil is not marketed as a weight loss supplement, a suppressed appetite may help you lose weight.

People use Metamucil primarily to increase their daily fiber intake. The supplement contains plant-based psyllium fiber from the Plantago ovata plant, which serves as a bulk-forming laxative. It promotes bowel movements and is a widely used treatment for constipation.

It is often recommended for patients with irritable bowel syndrome to relieve symptoms.

An adequate amount of fiber, in general, can help to prevent constipation. It can also support your weight loss goals by keeping you feeling full for longer. Other reasons for taking Metamucil include lowering cholesterol and promoting healthy blood sugar levels.

Are There Calories in Metamucil?

Yes, Metamucil contains calories. Metamucil comes in different forms, including powder, gummies, and capsules. All contain calories, but the number of calories differs between Metamucil products. For example, those with added sugar have more calories and carbs than sugar-free Metamucil. One serving of orange sugar-free powder Metamucil has 30 calories.

If you practice a strict intermittent fasting method and adhere to the rules, any number of calories will technically break a fast. Even a small number of calories can potentially interrupt your fasting journey.

Does Metamucil Spike Insulin Levels?

Whether Metamucil causes an insulin response depends on the Metamucil product you use. Those with psyllium husk as the only ingredient should not spike insulin levels, whereas other forms of Metamucil contain sugar and other carbs that will trigger an insulin response. It is especially important to avoid gummies as sugar in them will most definitely spike your insulin.

Psyllium husk is a soluble fiber. Soluble fibers dissolve in water and produce a gel-like consistency that helps slow glucose absorption in the digestive tract. For this reason, Metamucil fiber can help reduce sharp blood sugar spikes and support blood glucose control.

Can I Take Metamucil During the Eating Window?

Yes, you can consume Metamucil or another fiber supplement outside the fasting period. During the feeding windows, you can consume calories from foods, drinks, and supplements as part of a healthy meal plan. The contents of Metamucil will not affect your weight loss progress if taken at this time.

Taking Metamucil may even support your intermittent fasting plan. The fiber in Metamucil can help with appetite control so that you don’t feel hungry once your body is in a fasted state. Hunger pangs are a common problem among people practicing intermittent fasting.

A Word From a Nutritionist

Fiber supplements are a great way to increase your daily fiber intake. Fiber encourages regularity, aids weight loss, and helps lower blood glucose and cholesterol levels. However, if you’re doing intermittent fasting, knowing which supplements will break your fast is critical.

Essentially, you break a fast when you eat. A strict fast requires complete abstinence from food and drinks with calories. Introducing calories to your body can cause an insulin response that interrupts the fasting processes, kicking your body out of the fasted state.

However, taking such products during your eating windows may support a more comfortable fast by reducing hunger pangs and sugar cravings. You can also optimize supplementation in the eating windows to boost gut health and help mitigate digestive issues during a fast.

Some supplements can cause nausea if taken on an empty stomach. You should ensure adequate water intake if you decide to take certain dietary supplements in the fasting period. It’s also essential to avoid those with a high-calorie serving and high amounts of sugar.


So, does Metamucil break a fast?

Yes, it does because it contains calories and many Metamucil products also contain added sugar that will disrupt intermittent fasting. Our final thoughts on Metamucil are that you should avoid it during fasting and only consider this supplement in your eating window. If weight loss is your goal, there are other supplements you can try to boost your fasting progress.

Written by Edibel Quintero, RD
Edibel Quintero is a medical doctor who graduated in 2013 from the University of Zulia and has been working in her profession since then. She specializes in obesity and nutrition, physical rehabilitation, sports massage and post-operative rehabilitation. Edibel’s goal is to help people live healthier lives by educating them about food, exercise, mental wellness and other lifestyle choices that can improve their quality of life.
The article was fact checked by Rosmy Barrios, MD
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Written by Edibel Quintero, RD
Fact checked by Rosmy Barrios, MD
Last update: October 22, 2023
3 min read 1454 Views 0 Comments

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