Konnyaku, a foodstuff made from yam that is known for being ultralow in calories, is shaking off its humble image in Japan and getting a culinary makeover as consumers embrace it as a diet-friendly superfood.
In Gunma Prefecture, northwest of Tokyo, there is even a theme park dedicated to konnyaku where visitors can experience making konnyaku products by hand and help themselves to a buffet of konnyaku dishes free of charge.
"I don't feel guilty no matter how much I eat because it's so low in calories," said Mina Fujita, a 54-year-old office worker in Fukuoka, southwestern Japan, who has successfully used konnyaku to shed weight. "It's easy on the family budget, too."
Fujita began making konnyaku-based meals about 15 years ago, after learning of konnyaku's health benefits to suppress skin conditions such as atopic dermatitis, which her 22-year-old daughter suffers from.
Konnyaku, also known as devil's tongue and voodoo lily in English, increasingly became a family favorite as it can be cooked in various ways and has a texture they never grow tired of, she said.
She started using konnyaku for her own diet several years ago, experimenting with different dishes, such as a konnyaku "steak" and even "sashimi." She credits it with helping her lose 15 kilograms in about two and a half years.
A processed food made from the edible bulb of the konjac plant, konnyaku is believed to have been introduced from China as a medicine around the sixth century. Used in vegetarian cooking since the Muromachi period (1336-1573), it took off in popularity in the Edo era (1603-1868).
Yokoo Daily Foods, a konnyaku producer in the town of Kanra in Gunma that operates Konnyaku Park, says its buffet-style konnyaku has become such a hit that visitors to the amusement park occasionally see waits of up to two hours for their turn to eat.
Yokoo plans to expand the park site, which already features a mini Ferris wheel, games and some rides for small children, by autumn 2024, aiming to accommodate 1.5 million visitors annually.
The trend is even spreading abroad, with Japanese companies stepping up exports of a variety of konnyaku-based products such as noodles.
Nakaki Food Co. in Inazawa, Aichi Prefecture, began to export one of its signature products, konnyaku noodles, and other food products about seven years ago. In South Korea, its "konnyaku rice," containing a mixture of konnyaku and unpolished rice, became a top seller, with some 6 million packets sold yearly.
Nakaki held a special lecture at Nagoya Bunri University in Inazawa in November last year as part of the company's campaign to promote the domestic consumption of konnyaku.
Konnyaku has been primarily used in a supporting role in Japanese cooking, such as in oden or other hotpot dishes, but Toshikazu Nakamura, 70, president of Nakaki, says this dull image is quickly becoming a thing of the past.
"The image of konnyaku having a peculiar smell but no taste no longer applies," Nakamura said. "I wanted young people to learn about the allure of konnyaku," he added, referring to the event.
He said the students were eager to learn more about konnyaku, asking about its carbohydrate content and the most popular konnyaku products overseas.
Nakaki plans to release a retort pouch mixture of white rice and konnyaku as an alternative to white rice, targeting people with diabetes and other conditions that require they restrict their carbohydrate intake.
It is also developing a rice alternative in which all grains are manufactured from konnyaku.
"We hope to make konnyaku into one of the world's dietary staples," Nakamura said.
According to the Japan Konjac Association in Tokyo, which seeks to increase consumption of the healthy root to fight "lifestyle-related diseases," because konnyaku is low in calories and rich in dietary fiber, the more you eat it, the more you lose weight.
Konnyaku, which is usually a gray color with black specks or white, has a 97 percent water content, according to the JKA.
"It is the savior of problems with obesity today," said an association official.