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What is Konjac?
Konjac is a root vegetable traditionally used in East Asian and Southeast Asian countries (source).
It is also called “Elephant yam” or “Magic yam” in some local languages because of the root’s large size and its unique jelly-like textures when prepared in cuisines.
This humble looking plant has been studied and used as a therapeutic plant in Ancient China since 200BC. Modern science has also found many health benefits of konjac due to its unique nutrition composition.
Konjac Nutrition And Health Benefits
Konjac is very low in calories as it is mostly water, fiber, protein, and minerals. When added to foods such as pasta and jellies, it increases the volume of the food significantly with minimal addition of calories.
The “Magical” Fiber Glucomannan
Over half of konjac’s dry weight is from konjac glucomannan (KGM), a type of fiber in the tubers of the konjac plant. KGM is a soluble fiber, meaning that it absorbs water to form an elastic gel and generates very little energy in the body.
Konjac Glucomannan has many potential health benefits, as which are summarized here and described in more detail below:
- Konjac Glucomannan may help with satiety.
- Konjac Glucomannan may promote weight loss.
- Konjac Glucomannan is associated with improved blood glucose levels.
- Konjac Glucomannan may help lower cholesterol levels.
Satiety And Weight-Loss
The gel KGM forms can fill up the stomach quickly and delay stomach emptying, making it helpful in reducing energy intake and losing weight when added to foods.
In a recent Canadian study, participants who ate noodles containing KGM had 23% less calories intake at the meal compared to those who ate regular pasta, and felt the same fullness for hours after eating.
Another study has also found that adding glucomannan supplements to a lower energy diet resulted in more weight loss compared to the diet alone.
In addition, a systematic review of 14 studies concluded that KGM intake has significant benefit in weight-loss and other markers related to risks of chronic diseases.
Blood Sugar And Insulin Management
Since the KGM gel delays stomach emptying, it can also slow down the rise of blood sugar after meals.
One study found that for two groups of people with type 2 diabetes, the group that took KGM had lower blood sugar levels compared to the placebo group after taking glucose water. In another study, people with type 2 diabetes who took a KGM supplement for 1 month had 23% lower fasting blood sugar, a marker of insulin resistance, compared to those who took placebo.
Two other studies have also found that taking KGM-enriched biscuits instead of regular bran biscuits for 3 weeks improved serum fructosamine, an indicator of blood sugar levels, in people with type 2 diabetes and people with insulin resistance.
Lowering Blood Cholesterol
LDL cholesterol, the low-density lipoprotein, is also called “bad cholesterol” in the blood. It contributes to the fatty build-ups in the arteries, causing them to narrow, and increases risks for heart diseases and stroke. It is therefore crucial to maintain a healthy blood cholesterol ratio.
The studies mentioned above, along with a systematic review of twelve studies have also found that taking KGM long-term (>3 weeks) significantly reduced LDL-cholesterol and improved overall cholesterol ratio in both adults and children.
Promoting Gut Health
Just like many other soluble fibers, KGM has also been found beneficial in promoting bowel movement and gut health. It also acts as a prebiotic, as it is resistant to digestion and can be fermented by the intestinal microbiota.
Prebiotics promote the growth of beneficial bacteria in the gut, which is helpful for our gut health, immunity, and prevention of many diseases.
Konjac: The Special-Diet Friendly Ingredient
Konjac is suitable for many people following special diets:
- It is vegan and vegetarian.
- It can be included in a ketogenic diet.
- It is gluten-free.
- Although high in fiber, it is low FODMAP and generally well-tolerated in moderation.
Potential Side Effects Of Konjac
Konjac has a hard gel-like texture and doesn’t melt or dissolve in the mouth. Therefore, it requires adequate chewing and can pose a risk of choking or intestinal blockage. Risks are likely higher for infants, children, the elderly, and people with swallowing difficulties. Also, drink an adequate amount of water if you are eating foods containing konjac or taking KGM supplements as it absorbs water to expand.
Some people have reported abdominal discomfort, loose stools, or gas problems after taking KGM; but for most people, it is safe and tolerable in moderation.
Most clinical studies used between 2-3 grams of KGM per day on average, which is equivalent to around 100-125 grams of konjac noodles. A smaller amount is recommended to start if you have never tried konjac before.
If you are taking medications, eat konjac at least one hour after taking them as it slows down the absorption of the medicine.
Food Products Made With Konjac
In East Asia, konjac is used in many cuisines and food products, including konjac jelly, tofu, noodles, and stews.
In the west, konjac noodle is probably the main konjac food product available. Also called shirataki, these translucent noodles are traditional Japanese, but have become increasingly popular in many parts of the world recently because of the konjac’s health benefits.
Typically, these products are made with just konjac flour and water, while some types contain tofu. They are commonly found in the organic or plant-based sections of grocery stores, online health food stores, and on Amazon.
Ways To Prepare Konjac
The konjac noodles are easy to prepare. After taking them out of the package, all you need is to rinse them under cold water for 1-2 minutes to get rid of any unpleasant smell of the packaging liquid, and then boil them according to the package instruction.
You can also heat them dry in a pan or skillet after boiling to remove excess water if you are making noodle stir-fries or salads.
Konjac Recipes
Konjac noodles have no flavor of their own so they work well with pretty much any style! Enjoy konjac noodles as replacement of your favorite pasta, stir-fry noodles, or try some unique recipes inspired by different cultures:
- Butter And Parmesan Shirataki Noodles
- Konjac Noodles With Almond Butter Sauce
- Japanese Beef Sukiyaki (Beef And Vegetable Hotpot)
- Teriyaki Mushroom Shirataki Noodles
- Sichuan Style Spicy Konjac Salad
- Low Carb Konjac Pizza Crust
Bottom Line
Konjac is a great ingredient to include in recipes. It has very low calories and many health benefits in weight loss, blood sugar control, cholesterol levels, as well as gut health.
The food product of konjac, shirataki noodles are very easy to prepare and can be used in a variety of tasty and creative recipes.
Final thoughts:
- Did you learn more about this ingredient?
- Are you going to try konjac in the future?
- Which recipe do you think you’ll try?
Share in the comments below!
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Hello: I was just wondering if there has been any research on how knojac impacts the absorbtion of calories from other carbohydrates in food in which it is mixed or consumed at the same time? Does the high fiber content of konjac impacted how the body absorbs other calories from foods consumed at the same time during digestion? Hopefully that makes sense.
Hi Rich, I couldn’t find a specific study that answers this exact question. But I think the konjac (or other high fiber food or fiber supplement) would slow digestion and slow absorption of the calories from the other foods. This could slow down the body’s insulin response and contribute to feeling fuller longer. This could lead to lower calorie / less food intake in total, but the calories from that food that was eaten at the same time would still be the same. Unless of course, the high fiber was not well tolerated and the meal passed very quickly and not fully digested. That would be very unpleasant.