Healthy eating Okinawa style: A rainbow at the table

Okinawa is a model of healthy eating. The people on these small, subtropical Japanese islands live longer than those almost anywhere else in the world. And the evidence for this longevity is everywhere. Old Okinawans (and there are lots of them) are lithe and healthy looking, practising their daily exercises in the kind of fluid, well-rehearsed fashion that makes lesser mortals like myself shudder with shame at my half-hearted attempts at jogging. Or at least want to oil my creaky joints that bit more often.

So exactly which foods result in such long-lived well-being? Research shows that alongside traditional Japanese staples such as fish and seaweed, the secret is the rainbow of fruit and vegetables they consume, including such delights as purple sweet potatoes.

While we all know we should be eating our greens, it seems that in nutrition, green is not the only colour. Red, orange, purple and other colours have lots to offer too.

Bright colours are nature’s way of telling us that certain foods – superfoods – are packed with vitamins and minerals. The more vivid they are, the better they are.

So the best way to get all those nutrients and antioxidants is to eat from the whole spectrum, so you get your vitamin A from carrots and vitamin C from plump red peppers or purple berries, for example.

Because vitamins and minerals often work in pairs (we need vitamin C to absorb iron, for example), it’s no harm to brush up on which vitamins go with which minerals, and on what cooking brings out or destroys (the lycopene in tomatoes is more bio-available when they are cooked, for example). It’s all in the chemistry of the pairings, you see.

Think of it as nutritional speed dating.

But nutrition is just one consideration when cooking; flavour and ease of preparation are also important – which is where these two dishes come in.

Both are sufficiently nutritious to make you feel smug, but also have great depth of flavour and are easy to make.

Rich, velvety and filling, the soup is supper in a bowl. The butternut squash steaks are rather more fancy, but are perfect for a midweek treat or even as a veggie main course for a dinner party.

Removing and toasting the seeds is not compulsory, but it does let you feel that bit more accomplished. Just don’t expect anyone else to clap.