What is Japan’s Secret to Keeping Obesity Down and Life Expectancy Up?

Let's Explore the Relationship between Japanese Food and Wellness Benefits from Nutritional and Food Cultural  Perspectives

Japan became home to one of the world's longest living populations in the late 1970s (*2), and it is anticipated that the average life expectancy will continue to increase. Average life expectancy is influenced by many factors, such as medical care and living environment, but dietary habits have a large impact as well. As such, the Japanese diet has been a focal point when it comes to unlocking the secrets to Japanese longevity. 

The modern-day healthy nutritional balance of Japanese people consists of consuming moderate amounts of protein from fish, meat, and soy products, less fats and oils, and plenty of vegetables, seaweed, and grains. Originally, the Japanese diet was primarily vegetarian, consisting of soybeans, millet, vegetables, and seaweed, with a small amount of fish and the occasional addition of meat.  After World War II, people began to consume animal protein more frequently, which significantly extended life expectancy.

Fish has always been widely consumed in Japan. Although the Japan’s land area is small, the archipelago spans a lengthy distance, encapsulating many different climate zones. In addition, as the country is surrounded by sea on all sides, fish and seafood are easily available as a main source of protein.

Meat consumption was not originally popular in Japan, due in part to cultural reasons. Now, Wagyu beef is famous around the world, but it wasn't until after World War II that incorporating meat into diets really took off.

While meat consumption was not common, soybeans, as a source of protein, have been cultivated for thousands of years and been a staple of the Japanese diet since ancient times. The original forms of tofu, soy sauce, and miso were introduced from China, but these evolved uniquely in Japan to become the foundation of the Japanese diet. Not only are soybeans cooked and eaten as-is, but various innovations have been made, such as fermenting and processing into seasonings for storage over long periods of time. For this reason, soybeans are still frequently consumed in Japan.

The Japanese diet is characterized by various uses of soybeans and fish, and it is believed that these dietary habits help prevent vascular diseases such as myocardial infarction and contribute to longevity.

Soy sauce and miso, the key seasonings in Japanese cuisine, are both fermented seasonings made from soybeans. Fermenting soybeans generates complex flavors that bring out the deliciousness of ingredients. In addition to soy sauce and miso, Japanese cuisine often uses other fermented seasonings and foods such as mirin, sake, natto and tsukemono (pickled vegetables). Fermented foods contain umami components, lactic acid bacteria, yeast, and many other functional ingredients, which not only make these delicious but also help contribute to healthfulness.

"Umami" is the fifth taste after sweet, sour, salty, and bitter, and is responsible for the savory quality of food, and contains glutamic acid and inosinic acid. "Umami" is the Japanese word that describes deliciousness, and it is now used globally. Also, evidence is mounting that suggests umami not only enhances deliciousness, but also may promote health, such as by acting as a neurotransmitter for the secretion of digestive fluids.

In Japan, in order to maximize the deliciousness of ingredients, various approaches are used that combine ancient wisdom with the latest technology, and food continues to evolve to this day.

One example is "nerve-holding", a method of preparing fish to prevent the loss of components that impart umami, while another, "ice-temperature aging", is an approach to enhance the sweetness and umami of rice and sake by storing these at temperatures just before freezing. These are just a few of the ingenious techniques that go into Japanese cuisine.

These approaches of making the most of the ingredients reduce excessive seasoning during cooking, and are thought to be connected to the positive health effects of Washoku.

Graduated from the Faculty of Law at Gakushuin University and the Faculty of Nutrition at Japan Women's University of Nutrition. Completed her master's course at Tokyo Metropolitan University. After working in new business planning and development and menu planning at health-related companies, she went independent. Annaka provides product development support, healthy recipes, and nutritional information with a focus on food and health.