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Konjac foods are bounties to lose weight?

Michelle Lee, HK BioTek Intern

Konjac has been recognized by the World Health Organization (WHO) as one of the top ten healthy foods in the world. Konjac has almost zero calories. Eating Konjac foods can fulfil satiety, reduce calorie intake, and help in controlling weight. Many girls consume Konjac foods to replace regular meals for losing weight. It can reduce food intake, and hence their sugar and carbohydrate intake. It seems to be beneficial and harmless, but is it true?

Consumption of konjac in reasonable amount can increase satiety and help losing weight

Konjac foods are made from a plant called "konjac", it is a Japanese root vegetable that is full of fibre. Its texture is a bit like the common hotpot ingredient --- Konnyaku Noodle. The main ingredient is polysaccharides, which are water-soluble fibers. This water-soluble fiber is difficult to be digested and absorbed, so the calories are very low. The main component of konjac is Glucomannan, which contains 97% water and 3% dietary fiber. Konjac has low carbohydrate content and no fat, so it has very low calories, only about 10 calories per 100 grams, which is similar to that of vegetables. Konjac can swell up to 50 times after absorbing the water in the stomach and intestines. Ingesting a small amount of konjac can create a feeling of fullness, control food intake, and achieve a slimming effect.

Konjac has high fiber content, promotes defecation and improves constipation

Konjac is rich in dietary fiber, which can promote intestinal peristalsis and defecation to improve or prevent constipation, also to eliminate toxins from the body.

Konjac can reduce the accumulation of cholesterol and protect the cardiovascular system

Glucomannan can inhibit the absorption and utilization of cholesterol in the human body. The mucus protein contained in konjac can reduce the accumulation of cholesterol in the body. Therefore, proper consumption of konjac can prevent cardiovascular diseases to some extent.

Konjac foods can inhibit the rise of blood sugar and improve the situation of diabetes

Konjac foods actually have nutritional value, and contain water-soluble fiber, which is also beneficial to the intestines. The water-soluble fiber of konjac noodles helps to slow down the flow of food in the digestive tract, and prolong the retention time of food in the gastrointestinal tract. This can slow the rise of blood sugar, and stabilize blood sugar levels. For diabetics patients, konjac foods may help to control blood sugar under a properly planned diet. In addition, water-soluble fiber can be a nutrient source for beneficial bacteria in the intestinal tract. It can promote the reproduction of beneficial bacteria, and hence beneficial for human intestinal health.

Konjac foods are low in calories, so you don’t have to limit the intake, right? But there are some hidden health crises!

Dizziness and lack of energy: Most people think that replacing rice with konjac noodles will help to lose weight, but they don’t know that lack of carbohydrates (i.e. the major source of energy) can induce a big health crisis. Registered dietitian, Miss Jessa W.Y. Chow, pointed out that 50% to 60% of the individual daily calorie source comes from carbohydrates. Konjac can increase the feeling of fullness, but it cannot completely replace the grains in normal meals. Konjac contains only a small amount of carbohydrates. If we prolongedly consume Konjac to replace carbohydrates, it will cause nutritional imbalance, dizziness, muscle weakness, and lack of energy in the long run.

Not favourable for weight loss and keeping the body slim: We might think that we attain weight loss. However, it may slow down the body's metabolism, so only water and muscle in the body are lost, not fat. Decreased metabolic rate cannot help with weight loss and can easily cause weight rebound problems. Insufficient carbohydrate intake causes blood sugar to be too low. When the blood sugar is too low, we may want to eat more high-fat, high-sugar foods to meet the energy needs.

Konjac lacks the nutrients in meat: In addition, konjac cannot completely replace meat. The nutrients in meat, such as protein, iron and zinc, are very important to the human body. Consuming large amounts of konjac to completely replace meat can cause certain nutrient deficiencies, and other situations such as anemia, frequent fatigue, etc.

Weak limbs, rough skin, hair loss: In the absence of main carbohydrates, the body has to break down proteins in the body to provide energy. After a long time, the body tissues composed of protein, such as muscles, hair, skin, etc. will have problems. It may cause rough skin, hair loss, muscle weakness and loss, sarcopenia and other symptoms. In more serious cases, kidney functions may be impaired.

Konjac foods are diversified, but you should also pay attention to the calories in it

Konjac is highly plastic and can be made into a variety of konjac foods. People who love starch can also gradually establish a dietary model that uses konjac foods to reduce sugar. Konjac foods include konjac udon, spaghetti, ramen, vermicelli, etc., and even konjac rice. Now it is also equipped with different flavors of soup bases and seasoning packs to choose from, such as soy sauce, spicy, curry, Korean hot sauce and so on. In fact, konjac is made into different shapes of noodles by the processing factory, but the ingredients are the same. There are also konjac rice, konjac jelly and other products. However, some konjac products have added starch, soy protein and other flavors, which may slightly increase the calories of konjac products. Therefore, not all konjac products are low-calorie products.

Who are not suitable for eating Konjac foods?

People with poor gastrointestinal functions: In general, people should not consume more than one pack of konjac noodles per meal. It is recommended that the serving size should not exceed 50 grams per meal to avoid indigestion. People with poor digestion should not eat too much konjac, which contains a lot of dietary fiber. It can cause indigestion, bloating, stomach pain, etc. Indigestion can make the konjac foods being blocked in the stomach, causing stomach bloating and discomfort.

Diabetes patients taking blood sugar lowering drugs: When they eat konjac foods at first, they should measure their blood sugar level before eating. Alternatively, they can also take a small amount of starch (such as rice noodles) at the same time to avoid low blood sugar caused by dependence on konjac foods.

Elderly and children: Konjac is not easily digestible and must be chewed thoroughly when eating. There can be choking risk if the whole piece of konjac is swallowed without chewing. It will cause obstruction of the gastrointestinal tract. In severe cases, surgery must be performed to remove the blocked Konjac. Therefore, the elderly and children must be very careful during eating konjac foods.


Beware of the hidden sugars and calories of Konjac processed foods: Because konjac itself has no taste, a lot of sugar and sauces are added during manufacturing to increase the taste and flavours of Konjac. Moreover, Konjac has no taste, and most people eat Konjac foods with sauces. The sauces are high in fat and sodium content, which can cause obesity, edema, high blood pressure, etc. It is recommended that the daily sodium intake of a normal adult is not more than 2000 mg, in which, not more than 600 mg per meal. We should check the nutrition label when purchasing konjac products, and try to choose natural and unprocessed konjac foods. People who lose weight should choose konjac products that are natural, unprocessed and low in sugar.

Avoid drinking all the soup of Konjac products, reduce the amount of sauce and seasoning powder: Do not drink the soup base when eating konjac foods. If you cook konjac noodles without seasonings or sauces, you should avoid using too much high-sodium seasonings, such as fish sauce, chicken seasoning powder, and soy sauce. We can add natural seasonings, such as garlic, ginger, green onions, Chinese five spice powder, lemon juice and fresh chili, to replace high-sodium, high-fat sauces.

Konjac should not be consumed as a staple food: Konjac has low nutritional value and lacks important nutrients, such as carbohydrate, protein, and fat. Konjac is recommended to consume 100 grams per meal. Over-consumption of Konjac can cause malnutrition. For instance, Konjac noodles can be used as a dish or side dish to replace part of the starch or vegetables in meals, rather than completely replace the main dish, in order to assure enough nutrition and achieve the goal of weight loss. If konjac is used as a side dish, it is recommended to pair up with high-quality protein and vegetables to increase satiety. For example, Konjac can be served as a cold side dish with shiitake mushrooms, shredded pork, and seasonal vegetables.

Use tofu instead of konjac as a staple food: The texture and taste of tofu are slightly similar to that of konjac. Try using tofu instead of konjac as a staple food. Compared with other meats, rice, and noodles, tofu has relatively low calories and helps to lose weight. Tofu is rich in protein. Protein can increase satiety and reduce our appetite for high-calorie foods, such as starch and high-fat foods.


Konjac is not easily digestible, swells while absorbing water, and has low calories. At the same time, its water-soluble fiber content is quite high, making it a good source of dietary fiber. But always remember that don’t rely solely on konjac foods to lose weight. Taking konjac foods as a regular meal for a long time may cause fatigue, dizziness, body discomfort and other health problems.

A proper Konjac weight loss method is quite helpful for staying fit, controlling blood lipid level, blood sugar level, and solving constipation. Although Konjac can help to lose weight, it should not be consumed in excess. People with weak digestive abilities of the spleen and stomach should not consume Konjac frequently.

If you want to replace carbohydrates with konjac foods as your staple food, it is recommended to consume no more than 2 to 3 times a week. When eating konjac foods, you can also mix with other grain foods, such as udon, corn, etc., to ensure that you can fulfill the basic carbohydrates needs.


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