Does Shirataki Rice Have Side Effects? What You Need to Know

December 8, 2025 •

4 min read

Made from the konjac plant, shirataki rice is nearly calorie-free due to its high water and glucomannan fiber content. This unique composition also means that while beneficial for weight loss, shirataki rice has side effects that consumers should be aware of before adding it to their diet.

Quick Summary

Shirataki rice, derived from the konjac plant, contains high levels of soluble fiber (glucomannan) which can cause digestive issues such as gas and bloating. It is also low in nutrients, requiring a balanced diet.

Key Points

Digestive Distress: Shirataki rice is high in glucomannan fiber, which can cause bloating, gas, and loose stools, especially when first introduced into a diet.
Nutrient Deficiencies: The rice is very low in calories and nutrients; over-reliance can lead to deficiencies, so it must be part of a balanced diet.
Medication Interference: The glucomannan fiber can potentially reduce the absorption of oral medications, requiring careful timing of consumption relative to your medication schedule.
Gradual Introduction is Key: To minimize digestive side effects, start with small portions and increase intake gradually, while ensuring adequate water consumption.
Proper Preparation: Thoroughly rinsing and dry-toasting shirataki rice can remove excess moisture and reduce its signature odor, improving the texture and experience.
Not for Everyone: Individuals with sensitive digestive systems, those on certain diabetes medications, or people with swallowing disorders should be cautious.

Understanding Shirataki Rice: The Role of Glucomannan

Shirataki rice is a rice-like product made from the root of the konjac plant. Its primary component is glucomannan, a soluble dietary fiber that is highly absorbent and forms a gel-like substance when mixed with water. This is what gives shirataki rice its distinctive, slightly chewy texture and why it can expand in the stomach, creating a feeling of fullness. While this is a major benefit for those seeking weight loss, this very property is also the source of most of its potential side effects.

The Digestive Side Effects of Shirataki Rice

Bloating, Gas, and Diarrhea

For individuals unaccustomed to a high-fiber diet, the rapid increase in soluble fiber from shirataki rice can be a shock to the digestive system. As the glucomannan fiber ferments in the gut, it can produce gas, leading to bloating, flatulence, and general discomfort. While the fiber can help with constipation for some, others may experience the opposite effect, resulting in loose stools or diarrhea, particularly if consumed in large quantities. It is best to introduce shirataki rice gradually to allow your digestive system to adapt.

Rare Risk of Obstruction

While highly uncommon, especially with the water-packed rice, a risk of digestive system blockage has been associated with glucomannan in supplement form. This happens when the fiber swells before reaching the stomach. Because pre-packaged shirataki rice already contains a high amount of water, this risk is minimal but warrants caution for individuals with a history of swallowing difficulties or bowel obstructions.

Nutritional Considerations: Is Shirataki Rice Too Low in Nutrients?

Shirataki rice is lauded for its almost non-existent calorie and carbohydrate count, but this also means it contains very little nutritional value in terms of essential vitamins and minerals. Over-relying on shirataki rice as a staple food can lead to nutritional deficiencies if not balanced with other nutrient-dense foods. It is important to view shirataki rice as a vehicle for nutrients and flavor from other ingredients, such as vegetables, lean proteins, and healthy fats, rather than a primary source of sustenance.

Potential Interactions with Medications

Older research, mainly focusing on glucomannan supplementation, suggests that the fiber can interfere with the absorption of certain oral medications. The gel-forming properties of glucomannan can bind to medications, potentially reducing their effectiveness. If you take medication, it is advisable to speak with a healthcare provider or pharmacist about the appropriate timing of eating shirataki rice to ensure proper absorption.

How to Minimize the Side Effects of Shirataki Rice

To enjoy the benefits of shirataki rice without the potential downsides, consider these tips:

Start Small and Hydrate: Begin with a small portion and increase your intake slowly to help your body acclimate to the increased fiber. Always drink plenty of water when consuming high-fiber foods to aid digestion.
Rinse Thoroughly: Shirataki rice often has a distinct, slightly fishy odor when first opened. Rinsing it extensively under cold water can help minimize this and improve the overall experience.
Toast or Sauté: After rinsing, consider toasting or sautéing the rice in a dry pan for a few minutes. This can improve the texture and remove excess moisture.
Balance Your Plate: Incorporate shirataki rice into meals that include a variety of nutrient-dense foods, such as vegetables, lean protein, and healthy fats, to ensure a balanced diet.
Avoid Excessive Intake: Eating extremely large quantities of shirataki rice can increase the risk of digestive issues and other side effects. Moderation is key.

Shirataki Rice vs. Traditional Rice: A Comparison

To better understand how shirataki rice differs from its traditional counterparts, here is a comparison based on their nutritional properties:


Feature	Shirataki Rice	White Rice	Brown Rice
Primary Component	Glucomannan Fiber	Carbohydrates	Carbohydrates, Insoluble Fiber
Calories	Nearly Zero	High	Medium
Carbohydrates	Very Low (Net Carbs)	High	Medium
Fiber	Very High (Soluble)	Low	High (Insoluble)
Nutrients	Very Low	Low (Often Fortified)	High
Glycemic Index	Very Low	High	Low to Medium
Side Effects	Bloating, Gas, Diarrhea	Few	Minor digestive issues

Who Should Be Cautious with Shirataki Rice?

While generally safe, certain groups should exercise caution:

Individuals with Digestive Disorders: People with conditions like Irritable Bowel Syndrome (IBS) may find the high fiber content exacerbates symptoms.
Those on Diabetes Medication: The blood-sugar-lowering effect could cause hypoglycemia (blood sugar dropping too low) when combined with certain medications.
Pregnant and Breastfeeding Women: These individuals should consult a doctor before making significant dietary changes involving konjac products.
Anyone with Swallowing Disorders: The expanding nature of glucomannan, even when pre-packed with water, warrants caution for those with difficulty swallowing.

Conclusion: Balancing Benefits and Risks

Shirataki rice is a valuable food for those on low-carb or weight-loss diets due to its minimal caloric and carbohydrate content and high soluble fiber. However, as with any food, it is not without potential side effects. The high glucomannan fiber can cause digestive issues like bloating and gas, especially when consumed in large amounts or by those unaccustomed to high fiber intake. Furthermore, its low nutrient density requires a balanced diet to prevent deficiencies. By introducing it gradually, preparing it properly, and being mindful of portion sizes and overall nutritional balance, most people can safely and effectively incorporate shirataki rice into their meals. Individuals with pre-existing digestive conditions, those on diabetes medication, or those with swallowing disorders should consult a healthcare professional before regular consumption.

For more information on the effects of glucomannan, you can refer to a 2014 study on glucomannan supplementation that discusses potential side effects such as bloating, trapped gas, and diarrhea.

Frequently Asked Questions

The most common digestive side effects are bloating, gas, and diarrhea. These are caused by the high amount of soluble glucomannan fiber, which can ferment in the gut, especially in those unaccustomed to high-fiber diets.

While its fiber can help promote regularity, eating too much too quickly without enough water can, paradoxically, lead to constipation. It's crucial to stay hydrated when consuming high-fiber foods.

It is generally safe for most people to eat shirataki rice regularly as part of a balanced, nutrient-rich diet. However, daily intake should be monitored, and a doctor should be consulted if you have pre-existing digestive issues or take medication.

Individuals with pre-existing digestive disorders like IBS, people on certain diabetes medications, and pregnant or breastfeeding women should consult a doctor before consuming shirataki rice.

To reduce bloating, start with a small serving and gradually increase it over time. Ensure you drink plenty of water, and consider rinsing and dry-toasting the rice before adding it to your meals.

Shirataki rice has a neutral flavor, but it often has a mild, fishy odor when first removed from its packaging. A thorough rinse under cold water can eliminate this odor.

Yes, for individuals on diabetes medication, the fiber in shirataki rice can help lower blood sugar, potentially causing it to drop too low when combined with medication. It's important to consult a doctor.

Yes, proper preparation, including thoroughly rinsing the rice and possibly dry-toasting it, can improve its texture and mitigate potential issues associated with excess moisture and odor.