According to a new simulation study that used national dietary data, more Japanese adults are at risk of deviating from nutrient recommendations in the country’s Dietary Reference Intakes (DRIs) according to current dietary intakes – even though this simple issue could be solved by eating 200 grams of fruit and 350 grams of vegetables per day.
The authors, from the National Institutes of Biomedical Innovation, Health and Nutrition, say this intake would likely bring average dietary fibre and vitamin A up to target ranges. However, potassium would still lag and may require broader diet shifts.
The researchers analysed diet records from 4,927 adults in the 2019 National Health and Nutrition Survey (NHNS), a nationally representative, one-day, semi-weighed dietary survey run each November by the Ministry of Health, Labour and Welfare.
The analysis focused on nutrients that fruits and vegetables supply in Japan: dietary fibre, vitamin A, folate, vitamin C and potassium. Because the participants already exceeded DRI reference values for folate and vitamin C, the simulation centred on fibre, vitamin A and potassium. for vitamin A.
Current intake gap
The recommended consumption in Japan to prevent chronic diseases is 350 grams of vegetables and 100 grams of fruit daily, but according to this modelling study it will be impossible to reach public health targets based on current consumption habits.
This is because the baseline numbers from the NHNS show a wide gap — average intakes are about 100 grams of fruit and 281 grams of vegetables per day, while median fruit intake is only 55 grams and half of the study subjects consumed 250g of vegetables or less.
“Importantly, based on current numbers, 85.7% would fall short of targets set by the Japanese government [in the long run],” the study stated.
Japan’s previous national health programme Health Japan 21 was implemented between 2000 and 2020 to improve fruit and vegetable consumption across two 10-year phases, with the second phase aimed at reducing the share of people eating under 100 grams of fruit daily to 30%, while lifting average vegetable intake to at least 350 grams a day.
Unfortunately, more than two decades later, over 60% of adults still eat less than 100 grams of fruit, and 300 grams of vegetables daily.
Potential scenarios to reach DRI levels
The researchers built nine scenarios to raise the proportion of adults consuming at least 100, 150 or 200 grams of fruit to 70%, 80% or 90%. For participants already above the cut-off, the model used their observed intakes. For those below the cut-off, it assumed they reached the minimum cut-off and estimated the nutrients they would obtain from fruit based on current consumption patterns.
Next, the model calculated the extra vegetables needed — using today’s vegetable mix — to lift population averages to DRI thresholds for fibre, vitamin A and potassium. This step matters because in Japan’s diet, fruits and vegetables together provide a large share of fibre and vitamin A, but potassium is spread across many food groups, including grains, tubers, legumes, fish, meat, dairy, beverages and seasonings.
Across scenarios, results converged on a simple pattern: As more adults reached 200 grams of fruit intake per day, the average vegetable intake required to meet fibre and vitamin A targets settled at roughly 350 grams.
In the most ambitious scenario — over 90% of adults at 200 grams of daily fruit intake — the model estimated that about 350 grams of vegetables would “almost meet” the DRI reference values for fibre and vitamin A. The estimated daily average fruit intake in that scenario was about 200 grams.
Potassium remained short even in the 200 gram fruit intake scenarios. Because Japanese adults obtain potassium from many sources, boosting fruits and vegetables alone did not close the gap.
Meeting the potassium goal would likely require changes to staples and sides across the day, such as greater use of legumes, potatoes, leafy vegetables and dairy, along with reformulation where feasible.
Practical barriers and behaviour support
The baseline data showed that most adults needed to add at least 100 grams of fruit and around 70 grams of vegetables daily to reach the combined target. The paper pointed to behaviour-change tools that have worked elsewhere: social-norm messages in canteens and on social media, simple defaults in meal settings, and price incentives that lower the cost of pre-portioned produce. These approaches could make it easier to “do the right thing” without heavy cognitive effort.
Seasonality also matters. Fruit intake rises in autumn and the NHNS runs in November, so averages may look better than in other months. Additionally, any programme that pushes toward 200 grams of fruit daily should plan for supply and affordability throughout the year, not only during peak harvests.
“As the required intake of 200 g of fruits and 350 g of vegetables is far higher than the current Japanese intake, further research is needed to examine policies and interventions that may promote an increase in fruit and vegetable intake among the Japanese population,” said the authors.
Source: National Center for Biotechnology Information
“Simulation of the fruit and vegetable intakes meeting the dietary reference intakes of Japanese adults from the National Health and Nutrition Survey”
https://doi.org/10.1038/s41598-025-20710-6
Authors: Mai Matsumoto, et al.
