Paul Damian Madden (British Ambassador to Japan 2017-21) has talked about the importance of the geography of Japan has affected Japanese' character and behaviours. He mentioned in his speech that thanks to a good diet and healthy lifestyle, Japan has the world's highest life expectancy at around 85 years.
Traditional Japanese food is characterised by low-fat content, high consumption of soya products (tofu, natto, miso, etc.) and fish. And it is a highly nutritionally balanced diet with rice, whole grains, vegetables and seaweed as staples and very low sugar content.
Furthermore, compared with other developed countries in the world, the Japanese diet has a very low-fat intake, resulting in an extremely low obesity rate in Japan of only 4.3%, compared with 27.8% in the UK and 36.2% in the USA. Soya products, especially fermented soya products such as natto and miso, are highly nutritious for traditional and specific Japanese foods. When miso is fermented, the nutrients are transformed into smaller molecules for easier absorption. The probiotics in miso help regulate the intestinal environment, reducing stress, insomnia, skin problems, sensitivity to colds and the risk of colorectal cancer. In addition, the Japanese have a habit of drinking green tea, which is rich in antioxidants, boosts immunity, reduces the risk of cancer, improves digestion and blood pressure, improves brain function, and burns fat. All these traditional Japanese food allow the Japanese to live a long life with a healthy body.
Interestingly, in Paul Madden's speech, he mentioned in 2011 that the Japanese consumed more meat than fish or seafood for the first time, and that trend has continued. In fact, Japan did not already have the highest life expectancy in the world after 2012. That year, Hong Kong surpassed Japan to have the longest life expectancy in the world. The increase of consuming meat might be one reason Japan's life expectancy could not catch up with Hong Kong's increasing life expectancy rate.
Of course, there are many other reasons why the Japanese can live a long, healthy life and why Hong Kong has been able to slowly surpassed Japan and become the region with the world's highest life expectancy.
Findings show that food and eating habits are the secrets to longevity. The diet's content strongly reflects the region's history and ethnic group. Japan has maintained a high life expectancy since the 1960s because of advanced medical care and the eating habits of the Japanese people. The Japanese always eat a nutritionally balanced diet and low-fat foods. On the other hand, 80% of Hong Kong people did not achieve the WHO recommendation of at least 150 minutes of moderate-intensity aerobic exercise every week. Yet, Hong Kong became the region with the world's longest life expectancy due to the low smoking rate, taking Chinese herbal medicine for people of all ages to improve their constitutions over a long period, as well as very low medical costs.
I think the reason for the longevity of Japanese and Hong Konger is very different, Japan has a culture of having a healthy diet, and that's why many Japanese can live a long, healthy life. On the other hand, Hong Kong's life expectancy is high thanks to the good medical system and skills; not necessarily many of those long-living Hong Konger was living healthily at the end of their lives.
References
Macrotrends LLC. (2022). Japan Life Expectancy 1950-2022. Macrotrends.net. https://www.macrotrends.net/countries/JPN/japan/life-expectancy
公益財団法人長寿科学振興財団（2016） 日本人はなぜ長生きか | 健康長寿ネット. <https://www.tyojyu.or.jp/net/kenkou-tyoju/tyojyu-shakai/nagaiki.html>
魯皓平. (2021). 平均壽命總是全球最高！日本人分享他們長壽的7個祕訣. 遠見雜誌 - 前進的動力; 遠見天下文化出版股份有限公司. https://www.gvm.com.tw/article/82932
蘇冠米. (2021, November 4). 馬斯克發推「煮豆燃豆萁」！這些煮過的豆製品，對健康有益. 大紀元 Www.epochtimes.com. https://www.epochtimes.com/b5/21/11/4/n13351980.htm