There's a super food ingredient that they eat more of than anywhere else in the world, and today, I'm due to visit a revered master in the art of its production.

But before I meet him, I'm taking part in another of Japan's early morning rituals.

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Radio Exercise is a workout program that is broadcast nationwide every morning.

People either do the morning routine in their homes, or like these lovely lot, meet up in groups to do it.

This lady here is 93.

I think the average age is about 85 here.

But they learn these exercises in primary school.

So kids across the whole country do it.

The old age pensioners do exactly the same, and it's great.

Our kids should be doing it in Britain.

Daily exercise coupled with a healthy diet seems to be working wonders for Okinawans.

And there's one food they champion more than any other.

Okinawans eat more tofu than anyone else in the world.

And if you're not sold on tofu yet, then bear with me, because it's incredible, really, really nutritious.

And I'm going to get to meet a third-generation tofu maker that still makes it by hand.

55-year-old Shigaro Ngata is one of Okinawa's artisan tofu makers.

To make the tofu, he starts with dried soybeans and grinds them to produce a milk, which is decanted into these vessels, ready to be heated.

What temperature do we heat this to?

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The nigari, made from Japanese sea salt, causes the mixture to split into soy milk and curds, which is separated off to become tofu.

And I'm about to taste it freshly made, a rare treat.

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This is an opportunity that no one gets.

Oh.

Oh, it's really, really good.

The depth of flavor is unbelievable.

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This is the best tofu I've ever had in my life...Kyoto, Tokyo.

How important is tofu to Japan and Okinawan culture?

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Shigaro makes two types of tofu, the first is bags of super soft, silken tofu.

I've slowed him down a little bit today.

Okay? okay, okay.

So I'm going to have to do a little bit of work now.

For the second type, the curds are decanted into block molds and weighed down to remove the liquid.

This forms a more familiar, firm tofu.

One of the reasons Shigaro and Okinawans, young and old, may be living such healthy lives is because in a diet with very little meat, tofu is an important source of protein.

It's naturally lower in saturated fat and helps lower cholesterol.

If we're talking about the longevity and health of Okinawans, it's kind of impossible to rule out the important connection to tofu.

It's so prolific in their diet.

It's such an incredible protein.

This is definitely something that we should get in our life.