The Japanese diet is traditionally based on fresh, seasonal foods served in small portions and prepared with minimal processing. The traditional meal structure, called ichiju-sansai (one soup, three dishes), typically includes steamed rice, miso soup, one main dish (often fish or seafood), and two vegetable or soy-based side dishes.
This diet is naturally rich in vegetables, soy products, fish, seafood, seaweed, and fermented foods, which provide essential nutrients and support digestive, cardiovascular, and mental health. It encourages mindful eating and portion control, contributing to healthy weight maintenance and longevity.
Large population studies have linked adherence to the Japanese diet with lower risks of depression, heart disease, stroke, and premature death. These benefits are attributed to the combination of nutrient-dense plant foods, omega-3-rich fish, and fermented soy products.
What is the traditional Japanese diet?
The traditional Japanese diet, or Washoku, is a dietary pattern rooted in centuries-old culinary practices that focus on harmony between food, nature, and seasonality. Meals follow the ichiju-sansai format, which includes one soup, three dishes, and steamed rice, creating a nutritionally balanced combination of carbohydrates, proteins, fiber, vitamins, and minerals.
Core components are:
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Staple grain: Steamed short-grain rice
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Soup: Usually miso-based, sometimes clear broth
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Main dish: Typically grilled or simmered fish or seafood
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Side dishes: Seasonal vegetables, pickles, or soy-based foods like tofu or natto
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Beverages: Green tea or other unsweetened teas
The diet limits added sugars, animal fats, and heavily processed foods.
Health benefits
The Japanese diet is associated with benefits like:
1. Improved mental health
A large study of over 12,000 Japanese workers found that those adhering closely to traditional Japanese dietary patterns had a 17–20% lower risk of depressive symptoms compared to those with the lowest adherence. The protective effects are linked to omega-3 fatty acids from fish, fermented soy proteins, and folate-rich vegetables, which support brain function and neurotransmitter production.
2. Improved cardiovascular health
Meta-analyses show that following a Japanese-style diet can reduce mortality risk by 17% for cardiovascular disease, 20% for stroke, and 19% for heart disease. The average fish consumption in Japan provides about 1.3 g/day of omega-3 fatty acids, far above Western averages.
3. Increased longevity
A 15-year study of more than 75,000 adults found that people who most closely followed the Japanese diet had up to 15% lower risk of premature death compared to those eating a Western-style diet. Low rates of obesity, high intake of plant foods and fish, and minimal consumption of red meat contribute to Japan’s status as the world’s longest-lived nation.
4. Improved metabolic & digestive health
The diet’s high fiber content from vegetables, seaweed, and soy supports healthy digestion and satiety. Fermented foods like miso and natto help maintain a healthy gut microbiome, reducing gastrointestinal issues and supporting immune function.
Risks & considerations
The main nutritional concern with the Japanese diet is high sodium intake, mainly from soy sauce, miso, and pickled vegetables. Average daily sodium consumption in Japan exceeds WHO recommendations, which can increase the risk of hypertension, stroke, and stomach cancer.
Although miso’s bioactive compounds may partly offset its impact on blood pressure, people with hypertension, kidney disease, or cardiovascular conditions should limit sodium.
This eating pattern may also be unsuitable for pregnant or breastfeeding women, children, and those with a history of eating disorders unless adapted by a health professional.
How to start
The Japanese diet typically consists of three main meals a day: breakfast, lunch, and dinner, focusing on fresh vegetables, fish, soy products, and seafood. To adopt it gradually:
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Replace red meat with fish or seafood 2–3 times per week
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Incorporate soy foods like tofu, miso, or edamame
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Add seasonal vegetables to every meal
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Switch sugary drinks for green tea or water
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Follow Hara Hachi Bu—eat until you are 80% full
Meal preparation strategies include cooking rice in batches, making dashi stock ahead of time, and prepping vegetables for quick assembly.
Foods to eat
Foods in the Japanese diet are minimally processed and prepared to highlight their natural flavors:
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Fish and seafood: tilapia, sea bass, sardines, shrimp, squid, octopus
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Soy and derivatives: tofu, miso, natto, edamame
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Grains: rice, soba noodles
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Fruits: papaya, tangerine, orange, kiwi, pineapple, banana
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Vegetables: spinach, cabbage, bok choy, radish, pickled vegetables, peppers, tomatoes, bean sprouts, eggplant
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Seaweed: wakame, nori, kombu
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Beverages: water, green tea, matcha, black tea
Although they are not part of the Japanese diet, small amounts of red meat, chicken and eggs can be included in this diet.
Foods to avoid
Foods that should be eliminated or eaten in moderation include:
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Dairy products: milk, yogurt, butter, cheese
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Fatty cuts of red meat: rump steak, flank steak, lamb
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Excess fats: margarine, soybean oil, sunflower oil, ready-made sauces
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Sugary foods: sweetened cereals, cereal bars, candies, soft drinks
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Highly processed foods: fast food, frozen meals, ice cream
Avoiding these foods helps preserve the traditional balance of the Japanese diet and supports its health-promoting effects.
Sample 7-day plan
The following table outlines a 7-day meal plan for the Japanese diet:
This is just a model of the Japanese diet that varies according to each person's preferences. As it is a very restricted eating style, the Japanese diet should be followed for a short period of time and, preferably, with the help of a nutritionist.