Last year, my wife, young children and I moved back to Japan, from a long stint in Ireland, to live in the city of Hagi. We're on the rapidly depopulating coast of the Sea of Japan, away from modern hi-tech Japan, and I'm neck-deep in the novel. I don't really know what to do with the majority of foods in the supermarket here so my wife does most of the cooking. She's Japanese and cooks exclusively Japanese food. It's wonderful stuff - my favourite world cuisine. There's almost nothing I don't enjoy.

I first moved to Japan in 1994 and lived here for eight years. I still remember seeing grated dried tuna fish - katsuobushi - for the first time. It actually moves - it wriggles on hot tofu in the currents of steam. A few years later, we went to another traditional Japanese restaurant where the prawns that were brought out were so fresh they were still alive. You had to dismember your prawn and then eat it, feeling its death throes on your tongue. I still haven't quite got used to eating live fish.

I'm not a particularly adventurous cook, but I like roasting big trays of vegetables and using different flours like spelt flour to make bread in our bread-maker. For breakfast I either have toast made with homemade bread or a kind of everlasting cereal. I acquire different species of muesli and granola and feed bits at a time into a spaghetti jar. It's always different - you never know if you're going to get a bit of apricot you put in eight months ago or the nut granola you added yesterday. Then I go downstairs and work for a bit. We have lunch when our daughter gets back from kindergarten - udon noodles, or ramen. Mid-afternoon we have yokan, a sweet made from gelatinised white adzuki beans and sugar, which looks like a slab of jelly. It's delicious with green tea. We do try to eat healthily. Japanese food makes me feel particularly good. The most painless way of losing a few kilos I know of is to move to Japan, even allowing for their wonderful ice-cold beer! It's a Utopian, ultimate diet.

In Hagi fish comes in fresh every morning. The way of doing fish here is in a frying pan with a centimetre of the Holy Trinity of Japanese cuisine - sake, soy sauce, mirin - and then sugar and ginger, a sauce of heaven, so the bottom of the fish is boiled and the top is steamed. The Mebaru fish, which is known in English as Rock fish, is particularly good; or Tai fish, which is similar to sea bream.

Our Irish base in West Cork is a food heaven. There are a lot of alternative-thinking people, and that filters through to the cuisine. My wife cooks wonderful Japanese-accented food in Ireland with interesting local Irish substitutes. We get excellent venison sausages from the village, Unionhall. I was born in 1969, so I grew up straddling the amazing culinary revolution that happened in Britain in the Eighties. I've seen enough of the lean years of British food culture to enjoy the golden age of cuisine. The gustatory world is a much brighter place now.

Spelt bread

Wheat is a common cause of food intolerance symptoms such as fatigue and irritable bowel syndrome. Spelt wheat seems to be much better tolerated.

Green tea

Rich in disease-protective polyphenols, there is growing evidence that drinking green tea reduces the risk of developing several forms of cancer.

Venison sausages

I'm a fan of primal fare as it tends not to be intensively reared. Sausages can be sodium-rich, but the potassium in accompanying vegetables will help counteract the blood-pressure-raising effect

Mebaru/tai fish

This is also primal fare. Despite recent concerns about the contamination of fish, evidence suggests that eating it does us more good than harm.

Granola

I think breakfast cereals are massively overrated, but believe that muesli is the best option, partly because it is offers a broader spectrum of nutrients, especially David's ever-evolving muesli.

Yokan (adzuki bean sweets)

These have a very high content of added sugar, which is not beneficial for health, though the beans should offset this.

Udon or ramen noodles

Noodles are essentially made from refined wheat. As a general rule, I recommend that such foods should be used as an accompaniment to a meal, rather than the basis of one.

Japanese beer

As with wine, there is some evidence that beer-drinking is associated with a reduced risk of heart disease. David's moderate intake of beer is not likely to have much impact on his health.

· Black Swan Green by David Mitchell is published by Sceptre, £7.99