Misao Okawa was the oldest person in the world for almost two years between 2013 and 2015, living until the age of 117.

Before her death, she told the Japan Times that the key to a long life was "eating delicious things", including mackerel sushi, ramen noodles, and beef stew.

"Eat and sleep and you will live a long time," said the Japanese woman. "You have to learn to relax."

Years of research suggest that this is not just anecdotal.

There is a strong link between the food we consume to fuel our bodies, and the length of time that our bodies can stay healthy.

Scientists are especially interested in the food culture of Japan, which has the world's highest life expectancy at over 84 years. It is also the country with the most people living beyond the age of 100.

Studies show that eating a Japanese diet, made up of a balanced mixture of "vegetables, fruits, meat, fish, eggs, soy products, dairy products, confectionaries, and alcoholic beverages" can contribute to longevityThe fact of lasting a long time. When referring to populations and demography, it means living a long life..

The food journalist Michael PollanAmerican author and journalist. He explores the socio-cultural impacts of food in books, including The Botany of Desire and The Omnivore's Dilemma. summarised his principles as: "Eat food. Not too much. Mostly plants."

By "food", he means ingredients you can name, not overly processed substances found in modern Western eating.

The Japanese have followed these principles for thousands of years, with small portions and flavours of fermentation and soy dominating a largely fish, vegetable, and rice-based diet.

The Japanese government can take some credit for the longevity of its population. With one of the world's most rapidly ageing societies, the country needs its elderly to be able to work and stay healthy for longer.

Researchers found that participants who closely followed a government food guide had a 15% lower mortality rate.

In Okinawa - Japan's unusually centenarianSomeone who lives past the age of 100. In the UK, every centenarian receives a card from the Queen on their 100th birthday (as well as on their 105th and every year after that).-heavy southernmost islands - the inhabitants abide by "Hara Hachi Bu", an ancient principle that instructs people to only eat until they are 80% full.n

According to the BBC, "The way the Japanese serve their food is also key. Rather than having one large plate, they often eat from a small bowl and several different dishes." This variety allows people to enjoy a better range of nutrientsSubstances that plants and animals need to live and grow. The six essential nutrients our bodies need are vitamins, minerals, protein, fats, water, and carbohydrates. .

The process of healthy eating starts early. School children don't get to enjoy juice boxes or packed lunches. School meals are planned by nutritionists and eaten in front of teachers who help teach table manners. This leaves very little room for young people to become picky-eaters and develop unhealthy habits.

And it's not as though the Japanese eat unpleasant food. Tasty sushi, ramen, and bento boxes have now appeared all over the world.

Not necessarily. It's never as simple as just shopping from the Japanese aisle in a large supermarket. It's the spirit, not the ingredients. Portion size, preparation methods, exercise, and general lifestyle will also contribute to the health of the Japanese.

Yes. Traditional food cultures that have lasted for thousands of years have survived for a reason. The contemporary Western mode of eating - full of large portions, grains, and sugar - is known to cause harm to our bodies.