Xiaoyi Yuan

This study summarises the results of Japan's national pesticide residue monitoring program conducted between fiscal years 2013 and 2023. A total of 492,484 food samples were analysed, of which approximately 80% were imported. Annual sampling was consistent at approximately 55,000 samples. Analysis was conducted for more than 500 pesticide residues (mean: 474 per year), resulting in over 18 million pesticide-commodity combinations. Overall, 11.0% of the samples contained at least one detectable pesticide residue, and 0.28% were non-compliant with maximum residue limits. Fruits had the highest detection rates (36.0%) and multiple residues (16.5%), followed by herbs and spices (18.7% and 11.2%, respectively). In contrast, food products of animal origin had the lowest positive (2.3%) and non-compliance (0.05%) rates. The non-compliance rate exceeded 1% for nuts and seeds (1.6%). Residue detection did not consistently align with consumption: cherries showed a high detection rate (77.6%) but low consumption (0.2 g/day), whereas onions had a low detection rate (0.52%) despite high consumption (32 g/day). Frequently detected residues included neonicotinoids, pyrethroids, and fungicides, mainly from the demethylation inhibitor and strobilurin classes. These findings suggest that pesticide use in food commodities entering and distributed within Japan is appropriate and underscore the effectiveness of Japan's regulatory control over pesticide residues.

Regulatory bodies increasingly advocate probabilistic estimation of dietary exposure to better characterise variability and uncertainty. In response, we piloted a custom program tailored for Japan's regulatory context, using boscalid as a case study. Using Japan's national pesticide residue monitoring data (2013-2022) and food consumption data from a nationally representative survey (2016-2020) comprising 35,552 person-days from 4,444 individuals (including 861 children aged 1-6 years), we conducted Monte Carlo simulations with bootstrap re-sampling to characterise acute exposure distributions. Twenty-one food commodities with at least 25 positive samples or a positivity rate ≥20% were included. The results obtained from the custom program were compared with those obtained using concentration data simulated in Oracle Crystal Ball. At the 99.9th percentile, estimated acute exposures were well below the Acute Reference Dose: 0.12% (95% uncertainty interval: 0.11-0.14%) for general population (1-79 years) and 0.28% (95% uncertainty interval: 0.25-0.30%) for children aged 1-6 years. The results from the custom program and the Oracle Crystal Ball were comparable. These findings suggest that acute dietary exposure to boscalid is unlikely to pose a public health concern in Japan. The modelling framework developed here offers a practical foundation for more complex exposure assessments by Japanese regulatory bodies.

This study aimed to examine the relationship between the frequency of household shared meals and the intake of 17 food groups and 21 nutrients. Participants were 3310 men and 3386 women ≥20 years old living in a household of ≥2 members from 2018 and 2019 National Health and Nutrition Surveys in Japan. A one-day household dietary record was used to classify an individual’s shared meal frequency and dietary intake. A shared meal is defined as an eating occasion (i.e., breakfast, lunch, and dinner) where ≥1 food item—other than sugars, fats and oils, beverages, and condiments—was recorded with an assigned approximated shared proportion. The shared meal frequency for each individual was classified into one of four categories: 0, 1, 2, and 3 times/day. Dietary intake was compared across the shared meal categories adjusted for age, occupation, household size, meal skipping, snacking, residential areas, and within-household correlations. Both men and women who had more frequent shared meals showed higher intakes of potatoes, vegetables, mushrooms, and condiments but less confectioneries and beverages. A higher shared meal frequency was also related to a higher intake of many (12/21) nutrients (e.g., protein, dietary fiber, and potassium). However, in women, there was a positive association between shared meal frequency and sodium intake. A higher frequency of household shared meals may be related to a more favorable dietary intake; except for concerns about sodium intake in women.

This study aimed to compare the differences in the intake of food groups and nutrients between Japanese adults who consumed the recommended daily vegetable intake (350 g/day) and those who did not. Dietary information was obtained from one-day dietary records collected from the 2016 National Health and Nutrition Survey, which was conducted in 46 prefectures in Japan. The participants aged ≥20 years (n = 21,606; 53.8% women) were classified into the < and ≥350 g/day groups. Inter-group differences for 17 food groups and 27 nutrients were assessed as percentages of consumers (food groups only) and energy-adjusted intake (units/MJ/d or % of total energy intake). Overall, 29% of participants consumed ≥350 g/day of vegetables. The ≥350 g/day group had a higher percentage of consumers and energy-adjusted intakes for all vegetable subgroups than the <350 g/day group. For other food groups, the ≥350 g/day group had higher percentages of consumers for all food groups, except for cereals, eggs, and condiments and seasonings, which showed no significant differences. However, the ≥350 g/day group had a significantly higher energy-adjusted intake for potatoes and other tubers, mushrooms, meats, and condiments and seasonings but a significantly lower value for cereals, eggs, savoury snacks and confectionaries, and beverages. The ≥350 g/day group had a significantly higher intake of almost all (25/27) nutrients, including sodium, than the <350 g/day group. Participants with vegetable intake ≥350 g/day might have a more favourable intake of food groups and nutrients; however, watching for salt intake is necessary when promoting vegetable intake.

Background: We aimed to clarify whether differences in food group intake according to household income have changed over the last decade in Japanese people aged 20 years or older.Methods: This cross-sectional study was based on the 2010, 2014, and 2018 National Health and Nutrition Surveys in Japan. Food intake was assessed using a one-day semi-weighed household dietary record. The participants were categorized into three groups based on their income. The mean of each food intake according to the income group was estimated by adjusting for age, occupation, and number of participants from the same household. The significance of the interaction terms between income and survey year was evaluated to assess the change in income-related differences in food intake over time.Results: Cereal intake was lower in the middle- and the highest-income groups than in the lowest-income group, regardless of sex, and the interaction between income and year was insignificant for cereal intake. In the former two surveys, vegetable intake was higher among the highest-income women, while in the 2018 survey, the vegetable intake decreased in the women in the middle- and the highest-income groups. The interaction between income and year was significant for vegetable intake among the women. For other foods, the differences in intake among the income groups did not significantly change over time.Conclusions: The tendency for lower cereal intake in the higher-income groups was consistent over time in both the sexes and the tendency for higher vegetable intake in the highest income women disappeared over time.

To date, a limited number of studies have examined aspects of food choice values and food literacy in relation to some aspects of dietary behaviours. The aim of this cross-sectional study was to comprehensively examine the associations of food choice values and food literacy with diet quality. In total, 2231 Japanese adults aged 19–80 years completed questionnaires asking about food choice values (accessibility, convenience, health/weight control, tradition, sensory appeal, organic, comfort and safety) and food literacy characterised by nutrition knowledge, cooking skills, food skills and eating behaviours (hunger, food responsiveness, emotional overeating, enjoyment of food, satiety responsiveness, emotional undereating, food fussiness and slowness in eating). As a measure of diet quality, the Healthy Eating Index-2015 (HEI-2015) was calculated using a brief-type diet history questionnaire (BDHQ) or a food combination questionnaire (FCQ). In males, after adjustment for potential confounding factors (including age, BMI and the ratio of reported energy intake to estimated energy requirement), the HEI-2015 derived from BDHQ and that derived from FCQ were associated significantly (P ≤ 0·02) and positively with the food choice values of organic and inversely with food fussiness. In females, the HEI-2015 showed positive associations with the food choice values of health/weight control, nutrition knowledge and cooking skills and an inverse association with food fussiness, irrespective of the dietary assessment questionnaire (P ≤ 0·03). In conclusion, this study suggests that several aspects of food choice values and food literacy were associated with diet quality, and the aspects related differed between males and females.

Unlike in many industrialised countries, the high proportion of young women who are underweight in Japan has been a long-term problem. We evaluated trends in food group intake according to body size among young Japanese women using data from the National Health and Nutrition Survey 2001–2019. Overall, 13,771 Japanese women aged 20–39 years were included. A 1-day household-based dietary record was used to estimate food intake. Foods were classified into 34 groups based on the Standard Tables of Food Composition in Japan. The trend of food group intake was analysed using the Joinpoint Regression Program. The proportion of young women who were underweight was consistently around 20%, while obesity among young women increased between 2001 (10%) and 2019 (13%). A decreased trend in fish and shellfish and seaweed intake and an increased trend in meat and soft drink intake were observed among young women. Decreased trends in the intake of fruit and dairy products were observed in young women who were not obese. An increased trend in the intake of confectionaries was observed in young women who were obese. This study suggests that the types of unhealthy eating habits may differ according to body size among young Japanese women.

This cross-sectional study aimed to investigate the relationship between food sources of free sugars and weight status among children and adolescents aged 2–19 years in Japan (1438 males and 1340 females) from the 2016 National Health and Nutrition Survey, Japan. We estimated the percentage of energy intake (% E) from free sugars from total food sources (FS_total), solid foods (FS_solids), and beverages (FS_liquids), using one-day weighed dietary record data. Weight status was determined based on body mass index (BMI) z-scores and the prevalence of overweight and obesity. The mean energy intakes of FS_total, FS_solids, and FS_liquids were 5.8%, 4.1%, and 1.8% in males and 6.2%, 4.6%, and 1.6% in females, respectively. After controlling for potential confounding factors, including energy intake, there was no association of free sugars intake from all food sources with BMI z-scores or with the prevalence of overweight and obesity, except for a marginal association between higher FS_solids and lower estimated BMI z-scores in females (p = 0.05). The present findings indicate that among children and adolescents in Japan, who have a relatively low mean intake of free sugars, consuming free sugars from any food source is unlikely to have an adverse effect on weight status.