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Glucomannan for Weight Loss: How To Use It Correctly?

We know it—losing weight is hard. It takes effort, discipline, and time, among many other factors. It’s really no wonder why people are looking for ways to make their weight loss process a little bit easier.

Numerous brands have taken advantage of this struggle, and you can find a variety of weight loss supplements claiming to help you lose weight without any risks. Glucomannan is one of them.

But is glucomannan an effective weight loss aid, or is it just another trend? Let’s explore the evidence.

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What Is Glucomannan?

Konjac glucomannan (also known as KGM or simply glucomannan) is a natural, water-soluble dietary fiber that has been used as a food additive and dietary supplement for several decades. It can be found in products like flour, pasta, and the popular Japanese shirataki noodles. Glucomannan is extracted from the konjac plant, also known as the elephant yam.

One unique characteristic of this fiber is its ability to absorb waterit can hold up to 50 times its weight in water, making it one of the most viscous dietary fibers. When consumed, it expands in the stomach, helping you feel full and potentially aiding in weight management.

Intermittent fasting, a popular weight loss method, can be enhanced by adding glucomannan to your routine. This fiber may help relieve hunger pangs, a common reason people give up on their weight loss journeys.

By combining glucomannan with intermittent fasting, you can abstain from food for extended periods and improve the efficiency of your weight-reduction plan. 

If you want to follow the impact of glucomannan on your intermittent fasting experience, you can start tracking your weight loss journey today on the DoFasting app.

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How Does Glucomannan Affect Weight Loss?

Glucomannan has gained popularity in recent years for its purported weight loss benefits, particularly its ability to increase feelings of fullness and satiety.

However, it’s important to note that taking supplements with this fiber will not lead to weight loss on its own, as it is not a magic diet pill. Instead of treating it as such, consider using it as a tool that can promote weight loss in combination with a well-balanced diet, frequent exercise, and a healthy eating pattern.

Let’s dive into the different ways glucomannan contributes to weight loss.

Low in calories

Glucomannan may contribute to weight loss by helping you consume fewer calories. And, given its low-calorie content, it won’t significantly impact your overall calorie intake. Quite the contrary: when taken before a meal, glucomannan can promote feelings of fullness, which may lead to reduced food intake and weight loss.

Promotes the feeling of satiety

Glucomannan absorbs water and expands in your stomach, mimicking the feeling of fullness you get when you’ve had a big meal.

There are several ways you can take advantage of this unique effect:

  • Portion control — take a packet of glucomannan right before your meal. This way, glucomannan will take up some space in your stomach and make you feel full sooner. It’s an excellent way to eat less, especially if you tend to overeat.
  • Relieve hunger pangs — as mentioned previously, glucomannan can be helpful for people practicing intermittent fasting by reducing hunger pangs during a fasting window. This can be especially beneficial for beginners struggling to adapt to the new eating pattern.

Reduces appetite

Glucomannan can be an effective appetite suppressant because it creates a feeling of fullness in the stomach. As mentioned above, when it comes into contact with water and expands, it stretches the walls of the stomach, signaling to the brain that you have eaten a meal. Simply put, taking glucomannan is a way to trick your brain into thinking that you are full faster. 

It’s important to note that glucomannan should not be used as a replacement for a healthy, balanced diet, and that extreme calorie restriction is not a sustainable way to lose weight. Instead, consider using glucomannan as a supplement to support weight loss in combination with a well-balanced diet and regular exercise.

Reduces the absorption of protein and fat

Certain foods can make weight loss more difficult due to their high calorie, carbohydrate, and fat content. While these nutrients are essential and cannot be eliminated entirely from the diet, you can limit their impact on your body weight.

Fruits like apples, pears, and citrus fruits are good options for this. They contain a type of natural dietary fiber called pectin, which has been shown to reduce fat absorption in the gut.

Glucomannan, like other soluble fibers, can also minimize the amount of fat absorbed by your body’s cells. You can support your weight loss efforts by including it in your diet with other high-fiber foods.

Other Health Benefits of Glucomannan

In addition to its potential for weight loss, glucomannan has several other health benefits. Here are three benefits of this dietary fiber:

Lowers cholesterol

Glucomannan has the unique ability to reduce blood cholesterol by inhibiting its absorption in your gut. Studies have shown that glucomannan supplementation may improve your LDL cholesterol levels (also known as “bad” cholesterol), total cholesterol, and triglycerides. High LDL cholesterol levels have been linked to increased heart disease and stroke risk, so reducing it is especially beneficial for long-term health.

It’s important to note that no scientific evidence supports the claim that glucomannan can improve HDL cholesterol, also known as “good” cholesterol.

Lowers blood sugar

Glucomannan can help to regulate blood sugar levels by slowing down stomach emptying and delaying the absorption of carbohydrates. This can eventually improve insulin sensitivity and prevent fluctuations in blood sugar levels.

Maintaining a stable amount of blood sugar is essential for overall health, as high and low levels can cause serious health problems over time. In addition to improving sleep quality and mood, staying within the recommended sugar levels in your blood can also make weight management more accessible by reducing food cravings.

It’s important to note that glucomannan may not be an effective blood sugar management tool for individuals with impaired glucose metabolism. If you have concerns about the sugar levels in your blood or are at risk for developing diabetes, it is best to consult a healthcare professional for personalized advice.

Helps with constipation and promotes gut health

As a soluble fiber, glucomannan can help to relieve constipation and diarrhea by adding bulk to the stool and making it easier to pass. In a sense, glucomannan serves as a laxative. 

It is recommended to take 3 – 4 grams of glucomannan per day to relieve constipation, although it may take up to 24 hours to see results.

In addition to its laxative effects, glucomannan may also improve gut health. Some research suggests that it promotes the growth of beneficial gut bacteria, which is important for maintaining healthy microbiota and supporting the immune system.

Side Effects of Glucomannan

Glucomannan is generally considered safe when taken as directed. And although most people tolerate it, there are a few side effects to be aware of.

Possible side effects of glucomannan consumption include:

  • Stomach cramps
  • Bloating
  • Gas
  • Diarrhea
  • Esophageal or intestinal obstruction

To minimize the risk of obstruction, it is crucial to drink plenty of water when taking glucomannan supplements. Also, consider using glucomannan powder rather than pills, as these expand when in contact with water, increasing the risk of blockages.

It’s important to note that glucomannan may interfere with the absorption of certain medications, including those used to treat low blood sugar. To avoid this, the best course of action is to take glucomannan at least 4 hours after taking any medication.

If you are concerned about the potential interactions between glucomannan and your drugs, it is always best to consult a healthcare professional before starting a new supplement.

How Should You Take Glucomannan?

Research suggests that a daily dosage of 2 – 4 grams of glucomannan taken with a glass of water before meals may be effective for weight loss. 

When using glucomannan supplements to treat certain conditions, such as type 2 diabetes, insulin resistance, and dyslipidemia, the dosage is higher—between 4 to 13 grams per day. If you’re considering using glucomannan for these purposes, make sure to consult with your doctor first.

It’s important to note that these are just general recommendations. There are no official guidelines for how much glucomannan to take, so it is important to follow the instructions provided by the manufacturer of your chosen supplements. Always make sure to read these instructions and follow them closely.

Remember that, unlike other fiber supplements, glucomannan can absorb up to 50 times its weight in water and, if taken incorrectly, may block the throat and result in choking.

Best Sources of Glucomannan and Other Soluble Fiber

Soluble fiber is an important part of a healthy diet, as it slows down digestion and offers numerous health benefits, including improved heart and digestive health, as well as promoting a healthy gut by feeding beneficial bacteria in the large intestine.

Glucomannan is an excellent source of soluble fiber, but many other fiber-packed options are available in the market, such as vegetables, whole grains, and pasta. If you cannot tolerate glucomannan, these alternative sources of soluble fiber may be a good choice.

Shirataki noodles

Shirataki noodles are a common ingredient in Asian cuisine that has gained popularity in the West as a lower-calorie alternative to traditional pasta or noodles.

Just like glucomannan, shirataki noodles are made from the konjac root and are very low in calories, with a serving containing only about 10 calories and:

  • Carbohydrates: 3g
  • Sugars: 0g
  • Protein: 0g
  • Fiber: 3g
  • Fat: 0g

While shirataki noodles are low in calories, they’re also low in nutritional value—a delicious plate of shirataki noodles will not provide you with significant amounts of vitamins or minerals.

How to prepare shirataki noodles?

  • Take the noodles out of the bag and rinse them with water for about 30 seconds.
  • Drop them into a pot of boiling water for about 3 minutes.
  • Strain the noodles and cook them in a pan with the ingredients of your choice.

Beans and legumes

Beans and legumes are often recommended as sources of viscous dietary fiber. In addition to providing natural fiber, they are also high in plant protein and can be a good source of protein for vegetarians.

Numerous studies have shown that a legume-rich diet greatly reduces heart disease risk.

Here’s a list of high-fiber beans and legumes that you can find in any store:

  • Peas
  • Chickpeas
  • Soybeans
  • Black beans
  • Lentils
  • Peanuts

100 grams of these beans and legumes contain up to 10 grams of fiber, which, unlike a packet of glucomannan, will also provide you with essential nutrients.

Peanuts, for instance, are an excellent choice for a healthy snack. They can also be blended and added to a sauce or a salad.

Oats, rye, and barley

Oats, rye, and barley are cereal grains that have been praised by health experts for being rich in both soluble and insoluble fiber. Barley, in particular, contains high amounts of beta-glucan, a type of soluble fiber that has been shown to reduce cholesterol.

Let’s look at oats’ nutritional value as an example. A cup of oats holds 307 calories and contains:

  • Carbohydrates: 54.8g
  • Water: 8.78g
  • Sugars: 0.802g
  • Protein: 10.7g
  • Fiber: 8.18g
  • Fat: 5.3g

Oatmeal has been a staple breakfast choice for years, and it’s a great way to introduce fiber and healthy nutrients to your daily meals. These grains can also be incorporated into other meals as substitutes, like using barley in risotto or making your flour from oats.


It is essential to get soluble fiber from food, but fiber supplements can also be helpful for weight loss, especially for overweight individuals.

Fiber supplements in the form of pills or powder expand in your stomach, giving you the feeling of fullness and helping you control your food intake.

Glucomannan supplements can be beneficial when used in conjunction with intermittent fasting, as they can help suppress hunger pangs during the fasting window.

If you want to try this power combo, check out the DoFasting Appetite Suppressant, which contains 2 grams of glucomannan and cellulose per packet. Remember that it is essential to follow the recommended dosage and use these supplements as part of a healthy diet and exercise plan.

Glucomannan for Weight Loss: Final Considerations

Glucomannan can be an effective weight loss supplement when combined with a healthy diet and exercise plan. It helps you lose body weight by making you feel fuller faster, which can help prevent overeating and extend the time until you feel hungry again.

In addition to promoting weight loss, glucomannan may improve gut health, relieve constipation, reduce cholesterol, and reduce sugar levels.

However, it is essential to remember that glucomannan is not a magic solution and will not cause weight loss alone—it should be used as a tool in conjunction with other healthy lifestyle changes.


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This is an evidence-based article that includes scientific citations. DoFasting’s professional writers and editors prepared the content, which a team of medical experts verified to be accurate.

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