The benefits of protein to the human body have long been recognized by science, with collagen in particular finding favor with women who want to make their skin smoother and softer.
Japanese women - among the most image-conscious in the world - have taken to increasing their collagen intake in a very different way: from the inside.
In 2001, after 17 years of research into its properties, Kanebo Cosmetics was the first to launch a collagen beauty food in Japan, its Twany Collagen 5000 product delivering 5000 mg of the protein.
The success of the product was not lost on Kanebo's rivals and Meiji, Funcl, Shiseido and Lotte soon released similar supplements designed to make skin look younger and fresher.
"Collagen is a major structural protein of the skin and literally holds the body together," Shinji Yamada, a spokesman for Kanebo Cosmetics, told Relaxnews.
"The collagen molecule is composed of three polypeptide chains that wind around each other to form thick fibrils with enormous tensile strength," he said. "These fibrils form a sturdy 'scaffolding,' or matrix, that supports cells, tissues and bones, providing a vital framework while ensuring the smooth functioning of organs and limbs.
"In the skin, collagen is produced by specialized cells in the dermis called fibroblasts," he added. "The collagen produced here acts as a cushion for the skin surface, contributing to the smooth, firm, 'plumped-up' appearance of young, healthy skin.
According to a study by industry analysis firm Fuji Keizai, the market for products containing collagen, including health food, beauty food and supplements, more than doubled between 2005 and 2008, increasing from Y17.2 billion (€130.4 million) to Y37.1 billion (€281.3 million).
Restaurants have also been quick to realize the benefits of having collagen-laden items on their menu, including dishes such as shark fin, pigs' trotters and chicken skin marketed as anti-aging specials.
Harunohi started out as a single restaurant specializing in healthy food, but has since grown into a chain across Tokyo.
"A 'nabe' is a type of traditional Japanese hot pot and it's one of our most popular dishes," said Eri Fujimoto, a spokesperson for the chain. "Our first restaurant started about three-and-a-half years ago and we quickly became popular with women ordering these dishes because they are concerned about their skin and their diet in general."
The collagen is extracted from boiled chicken bones and made into a solid when cooled. It is then added to the "Beauty nabe," along with vegetables for a healthy and inexpensive meal, Fujimoto added.
Elsewhere, food companies are adding collagen to their lines of marshmallows, cheesecake, soups and soft drinks - with Kowa's incredibly popular Fracora 500 fish collagen drink selling an incredible 55 million bottles since it was released in 2004.