Last updated: August 30, 2021

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A healthy appetite is essential for maximum vitality and good health. Unfortunately, a love of fast food can sometimes throw your best weight loss plans out the window. Does losing weight have to mean suffering? How do you resist temptation?

Glucomannan-based food supplements provide plant-based fiber. This non-absorbable material is essential to maintain good intestinal health. And, if you have started a weight loss diet, this substance could keep your appetite at bay. Curious to discover all the secrets of glucomannan? Keep reading!




Key Facts

  • Glucomannan is extracted from the plant Amorphophallus konjac. It is made of highly soluble fiber, multiplying its volume when in contact with water.
  • Glucomannan is recommended by Dr. Oz for weight loss. However, the most current studies have questioned some of its benefits.
  • When buying a glucomannan supplement, you should consider your dietary restrictions, the presence of additional ingredients and their value for money.

Our Selection: The Best Glucomannan Supplements

Choosing a glucomannan-based nutritional supplement can be difficult. This product is sold in numerous different formats and in combination with other substances. Check out this section to discover our list of the best glucomannan products according to our experts.

Shopping Guide: Everything You Need to Know about Glucomannan

Glucomannan is a plant compound that provides large amounts of fiber. Food supplements based on this substance increase in volume when in contact with water, so consuming it decreases appetite and promotes digestion. These properties have made glucomannan a popular weight loss remedy.

girl with food

Glucomannan could interfere with the absorption of other drugs.
(Source: Dolmatov: 91906922/ 123rf.com)

What is glucomannan and how does it work?

Konjac glucomannan, better known as glucomannan, is a substance from the Asian plant Amorphophallus konjac. The extract of this vegetable produces a very soluble type of fiber, capable of absorbing large amounts of water and increasing its volume significantly.

This phenomenon also occurs in the human intestinal tract.

The swelling of ingested glucomannan causes a feeling of fullness in the stomach. In addition, by increasing the mass of non-absorbable intestinal content (or fiber), this substance improves intestinal transit. Being a viscous substance, it also hinders the absorption of sugars and other nutrients (1).

How does glucomannan help you lose weight?

Amorphophallus konjac has been used in Asian gastronomy to make flours and pastries over centuries. The dried fiber of this plant is used as a satiety and as a promoter of intestinal transit. In today's market, you can find glucomannan as a supplement that promotes weight loss.

The European Food Safety Authority (EFSA) found that this food supplement can significantly improve certain body parameters, including weight. We have included a summary of this study in the following table:

Objective studied Good results?
Weight loss Yes
Blood glucose control No
Decreased fat absorption No
Cholesterol control Yes
Improvement of digestion Yes
Probiotic or prebiotic action No 

During this compilation of clinical studies, experts found that data on the slimming properties of glucomannan are inconsistent. After carefully analyzing data on this food supplement, the authors of the meta-analysis reached the following conclusions (3): Thus, EFSA found that glucomannan (minimum dose of 3 grams) may contribute to the weight loss and cholesterol control. The organization also warns that this supplement will be useful only if used in combination with a hypocaloric diet. However, a 2014 meta-analysis puts these alleged benefits into question.

  • The weight loss associated with glucomannan consumption is not significant.
  • Glucomannan does seem to be related to better control of the lipid profile (cholesterol).
  • There does not seem to be a linear relationship between the dose of glucomannan consumed and weight loss. That is, a higher dose of konjac is not always more effective in losing weight.
  • The duration of the analyzed studies (8-12 weeks) was considered too short. Longer treatments may have had different results.
  • More data is needed to confirm or deny the alleged effects of glucomannan on weight and metabolism.

What other uses does glucomannan have?

As we have mentioned, glucomannan is a type of dietary fiber. This term refers to edible products that our body is unable to process. Although the nutritional content of fiber is negligible, it is invaluable for our health. The following list summarizes its main benefits (4):

  • Decreased cholesterol and triglyceride levels
  • Lowering blood pressure
  • Optimization of blood sugar control
  • Improvement of digestion
  • Weight loss
  • Immunity boosting

Generally, a consumption of between 28 and 36 grams of fiber per day is recommended. Unfortunately, a diet that is poor in vegetables, fruits, and whole foods provides very low amounts of dietary fiber. In these cases, glucomannan could help to improve digestion.

Studies linking glucomannan with weight loss have been conducted in people considered obese or overweight. If you are at a healthy weight, konjac fiber will not eliminate localized fat or cellulite. However, it will help you feel more vital and healthy.(5).

girl with stomachache

Glucomannan is also used to improve digestion.
(Source: Twinsterphoto: 104225661/ 123rf.com)

What kind of glucomannan-based products are there?

The most interesting thing about Konjac glucomannan is its versatility. You can find this product, like other nutritional supplements, in capsules or in powder. Furthermore, the dissected extract of this root can also be used to make flour that can be used to prepare different dishes (1).

If you are on a low carbohydrate diet, you'll be glad to know that there are low-calorie glucomannan alternatives. Pasta and rice based on konjac provide less than 12 calories per 100 grams on average and up to 50% of its composition is fiber.

However, some nutrition experts are cautious about these products.

Excessive consumption of glucomannan may impede the absorption of other nutrients. Also, the ingredients used to improve the flavor of konjac may be more caloric than its starchy alternative.

You can also find glucomannan-based products in the form of tablets and jelly beans. We strongly discourage this, however, as it has been linked to suffocation and airway obstruction. This type is especially dangerous for children, the elderly and people suffering from diseases that affect swallowing (6).

food

Glucomannan flour can be used to make low-calorie pasta and rice.
(Source: Balabanova: 90142371/ 123rf.com)

How do you use glucomannan?

Depending on the format of your glucomannan-based food supplement, you should use it in one way or another. Konjac root extract dosage is also considered important. The relationship between weight loss and grams of glucomannan ingested per day is somewhat random.

Grams of glucomannan (daily) Maximum weight loss (after 8 - 12 weeks)
1.0
1.5 0
2 1
3 4

Hydrate: It is very important to consume large amounts of water while taking glucomannan. This way, it will enhance its satiating effect and avoid adverse effects such as obstruction in your throat. It is typically recommended to consume a total of 3 g of glucomannan a day, divided into three doses before the main meals. If instead of powder or capsules you use food substitutes, you should take a few things into account:

  • Watch the additives: Foods rich in carbohydrates are very tasty. Food based on konjac flour has a tolerable flavor, but it is not very intense. If you try to spice up your dishes using high calorie sauces, you could end up gaining weight instead of losing it.
  • Maintain good nutrition: You can use glucomannan as a substitute for fast food. However, if you substitute all your meals for konjac, you will stop consuming essential nutrients for maintaining good health. Use it sparingly!

Glucomannan can help you control your appetite, making it easier for you to reach your weight loss goals. However, this food supplement will not be useful if you do not accompany it with a low calorie diet, combined with an adequate exercise program. Remember that there are no "magic pills" to lose weight.

Is glucomannan dangerous?

Konjac glucomannan is generally considered safe for use. In clinical trials, it has been used for up to 12 weeks without producing noticeable toxic effects (7). However, this compound is not without adverse effects. These undesirable reactions are summarized in the following table (6):

Common adverse effects Rare side effects
Diarrhea Asthma
Abdominal bloating Liver problems
Upset stomach Choking
Hypoglycemia in diabetics Constipation

You should use this food supplement consciously if you want to avoid any unpleasant effects. Don't forget that, despite being a natural ingredient, Konjac glucomannan is a foreign substance to the human body. As such, it should be used responsibly for the shortest time necessary to achieve your goals:

  • Common side effects: The most common effects (glucomannan fiber intolerance) can be avoided by decreasing the amount of konjac ingested. It has been seen that intestinal discomfort is much more frequent if doses of this supplement are greater than 5 grams daily. Basically, don't make glucomannan your only source of fiber.
  • Hypoglycemia: The interaction of glucomannan with antidiabetic medication can alter its effectiveness. In addition, this supplement can also delay the absorption of food with glucose. Diabetics should not use this supplement without the authorization of a doctor, as they could suffer a dangerous imbalance in their plasma glucose.
  • Asthma and liver disease: Less common (but more serious) problems are more difficult to anticipate. Fortunately, they are rare. If discomfort, shortness of breath or yellowing of the skin appears, stop taking glucomannan and seek a health professional as soon as possible.
  • Choking and suffocation: These life-threatening complications can occur if large amounts of solid glucomannan are ingested. It is very important to drink large amounts of water after ingesting konjac to avoid this effect. Also, children, the elderly and the sick should avoid glucomannan (especially in tablets).

Remember to consume glucomannan at least four hours before or after your usual medication to avoid effects on its absorption. The influence of this food supplement on the metabolism of pregnant or lactating women is unknown. For this reason, it is not recommended without supervision in these cases.

glucomannan

Glucomannan could lower cholesterol levels.
(Source: Barmalini: 129038129/ 123rf.com)

Buyers Guide

Now that you know everything you need to know about glucomannan, you know how important it is to choose the right product. Read this section carefully to find tips to help you find a safe and affordable konjac glucomannan food supplement.

Dietary Intolerances

The vegetable origin of glucomannan makes this compound suitable for vegans in most cases. Pay attention to other compounds that your capsule may contain, as these additives may contain animal products. Many glucomannan products contain gluten. If you are celiac, check the labeling well.

gluconmannan

You can find a variety of additional ingredients in slimming, fat-burning or fat-reducing foods.
(Source: Balabanova: 95724133/ 123rf.com)

Format

Remember, it is best to avoid solid glucomannan tablets to minimize the risk of suffocation. The capsules should always be consumed with at least two glasses of water per dose. If you're afraid of forgetting to drink enough liquid, konjac smoothie powder (which requires adding water in advance) might be a good option.

Other Ingredients

You can find a variety of additional ingredients in slimming, fat-burning or fat-reducing supplements. You can also find combinations with vitamins and minerals that promote normal metabolism. However, be aware that glucomannan may impede the absorption of these nutrients.

Metabolic reactions resulting from the combination of various weight loss supplements can have unpredictable effects. We generally do not recommend these combinations. If you are determined to make use of various weight loss supplements, the combination of Garcinia cambogia and glucomannan appears to be safe (8).

Did you know that one gram of glucomannan can absorb up to two hundred milliliters of water, increasing its volume and contributing to the feeling of fullness?

Conservation and Expiration

Consuming expired glucomannan is not dangerous. However, konjac-based substitutes will lose their structure about two to three months after the expiration date, becoming inedible. Store your glucomannan supplements in a cool, dry place. And make sure they do not come into contact with liquids.

Summary

We all know the importance of fiber in a healthy diet. However, few of us think about using the satiating power of it to control our weight. Konjac glucomannan allows you to get the most out of your fiber, improving your digestion while reducing your appetite.

Don't forget that your perseverance and dedication will be your main tools in your journey to lose weight. Glucomannan would be, in this case, one more tool. And if you have already met your weight loss goal, why not let it help you normalize your digestion?

(Source of featured image: Leelaic: 34124117/ 123rf.com)

References (8)

1. Maia-Landim A, Ramírez JM, Lancho C, Poblador MS, Lancho JL. Long-term effects of Garcinia cambogia/Glucomannan on weight loss in people with obesity, PLIN4, FTO and Trp64Arg polymorphisms. BMC Complement Altern Med [Internet]. 2018 Dec 24 [cited 2019 Dec 8];18(1):26.
Source

2. Vita PM, Restelli A, Caspani P, Klinger R. [Chronic use of glucomannan in the dietary treatment of severe obesity]. Minerva Med [Internet]. 1992 Mar [cited 2019 Dec 8];83(3):135–9.
Source

3. Glucomannan Uses, Benefits & Dosage - Drugs.com Herbal Database [Internet]. 2002 [cited 2019 Dec 8].
Source

4. Chen HL, Cheng HC, Liu YJ, Liu SY, Wu WT. Konjac acts as a natural laxative by increasing stool bulk and improving colonic ecology in healthy adults. Nutrition [Internet]. 2006 Nov [cited 2019 Dec 8];22(11–12):1112–9.
Source

5. Siegel JD, Di Palma JA. Medical treatment of constipation. Vol. 18, Clinics in Colon and Rectal Surgery. 2005. p. 76–80.
Source

6. Onakpoya I, Posadzki P, Ernst E. The Efficacy of Glucomannan Supplementation in Overweight and Obesity: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Am Coll Nutr. 2014 Feb;33(1):70–8.
Source

7. Scientific Opinion on the substantiation of health claims related to konjac mannan (glucomannan) and reduction of body weight (ID 854, 1556, 3725), reduction of post-prandial glycaemic responses (ID 1559), maintenance of normal blood glucose concentration. EFSA J [Internet]. 2010 Oct [cited 2019 Dec 8];8(10):1798.
Source

8. González Canga A, Fernández Martínez N, Sahagún AM, García Vieitez JJ, Díez Liébana MJ, Calle Pardo ÁP, et al. Glucomanano: Propiedades y aplicaciones terapéuticas [Internet]. Vol. 19, Nutricion Hospitalaria. 2004 [cited 2019 Dec 8]. p. 45–50.
Source

Why you can trust me?

Estudio científico
Maia-Landim A, Ramírez JM, Lancho C, Poblador MS, Lancho JL. Long-term effects of Garcinia cambogia/Glucomannan on weight loss in people with obesity, PLIN4, FTO and Trp64Arg polymorphisms. BMC Complement Altern Med [Internet]. 2018 Dec 24 [cited 2019 Dec 8];18(1):26.
Go to source
Estudio científico
Vita PM, Restelli A, Caspani P, Klinger R. [Chronic use of glucomannan in the dietary treatment of severe obesity]. Minerva Med [Internet]. 1992 Mar [cited 2019 Dec 8];83(3):135–9.
Go to source
Web oficial
Glucomannan Uses, Benefits & Dosage - Drugs.com Herbal Database [Internet]. 2002 [cited 2019 Dec 8].
Go to source
Ensayo clínico
Chen HL, Cheng HC, Liu YJ, Liu SY, Wu WT. Konjac acts as a natural laxative by increasing stool bulk and improving colonic ecology in healthy adults. Nutrition [Internet]. 2006 Nov [cited 2019 Dec 8];22(11–12):1112–9.
Go to source
Estudio científico
Siegel JD, Di Palma JA. Medical treatment of constipation. Vol. 18, Clinics in Colon and Rectal Surgery. 2005. p. 76–80.
Go to source
Revisión sistemática
Onakpoya I, Posadzki P, Ernst E. The Efficacy of Glucomannan Supplementation in Overweight and Obesity: A Systematic Review and Meta-Analysis of Randomized Clinical Trials. J Am Coll Nutr. 2014 Feb;33(1):70–8.
Go to source
Comunicado organismo oficial (EFSA)
Scientific Opinion on the substantiation of health claims related to konjac mannan (glucomannan) and reduction of body weight (ID 854, 1556, 3725), reduction of post-prandial glycaemic responses (ID 1559), maintenance of normal blood glucose concentration. EFSA J [Internet]. 2010 Oct [cited 2019 Dec 8];8(10):1798.
Go to source
Artículo de revisión
González Canga A, Fernández Martínez N, Sahagún AM, García Vieitez JJ, Díez Liébana MJ, Calle Pardo ÁP, et al. Glucomanano: Propiedades y aplicaciones terapéuticas [Internet]. Vol. 19, Nutricion Hospitalaria. 2004 [cited 2019 Dec 8]. p. 45–50.
Go to source
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