Background: Seasonal variations could systematically bias dietary intakes. This systematic review aimed to determine seasonal variations in dietary intake among Japanese adults.

Methods: PubMed and Ichushi-Web databases were searched for studies reporting seasonal intakes of nutrients or food groups assessed using dietary records or 24-hour recalls. The protocol was registered with PROSPERO (CRD42022356084).

Results: Ten studies (eight studies on 1–31 nutrients and four on 2–15 food groups) met the inclusion criteria. Six studies included both sexes, whereas four investigated only females. The number of participants ranged from 25 to 459, and the number of dietary survey days in each season ranged from 1 to 14. For most nutrient and food groups, the reported seasonal variations were inconsistent across studies. The meta-analyses comparing differences in mean intakes between two seasons showed no significant differences in all comparisons or differences in only one comparison for most nutrients and food groups. Significant seasonal differences were observed for vegetables, fruits, and potatoes in five out of six comparisons, though the heterogeneity was high. Their biggest differences were as follows: 101 g/day more vegetable intake in summer than spring, 60 g/day more fruit intake in fall than spring, and 20.1 g/day more potato intake in fall than spring.

Conclusion: Reported seasonal variations were inconsistent across studies for most food groups and nutrients. Relatively distinct seasonal differences in mean intakes were observed for vegetables, fruits, and potatoes in meta-analyses. However, these results must be interpreted cautiously because of the high heterogeneity and limited representativeness.

Background: The lockdowns imposed by the government during coronavirus disease 2019 (COVID-19) pandemic have had a significant impact on the Italian population habits.

Methods: LOckdown and lifeSTyles in Italy and in Tuscany studies collected data on a representative sample of the Italian adult population in 2020 (n = 6,003) followed up through 2023 via four additional surveys (3,000 ≤ n ≤ 6,600) through an online self-administered questionnaire. The Alcohol Use Disorders Identification Test-Concise was used to identify at-risk drinkers. Considering the cohort of individuals who took part to the first and at least one other wave (n = 5,378), a multilevel logistic model was used to derive odds ratios (ORs) and corresponding 95% confidence intervals (CIs) of being at-risk drinkers.

Results: The prevalence of at-risk drinkers was 26.4% before, 23.4% during the first lockdown, and stabilized around 30.0% thereafter. Being at-risk alcohol consumers decreased with decreasing economic status (P for trend <0.001), was less frequent among middle-aged compared to younger (OR 0.73; 95% CI, 0.60–0.89) and among divorced/separated (OR 0.77; 95% CI, 0.60–0.99) or single (OR 0.75; 95% CI, 0.64–0.89) compared to married individuals. It was more frequent among individuals with anxiety or depressive symptoms (OR 1.24; 95% CI, 1.12–1.37), those using psychotropic drugs (OR 1.99; 95% CI, 1.69–2.35) and users of conventional and/or alternative nicotine products (OR 3.67; 95% CI, 3.00–4.48).

Conclusion: The long-term trends in alcohol consumption after the COVID-19 pandemic are unfavorable in Italy. The results point to an increased vulnerability for at-risk alcohol consumption among younger individuals, women with higher economic status, and married individuals. At-risk drinking is strongly related to mental health symptoms and nicotine consumption.

Background: To date, a simple assessment tool to evaluate early low nutrition risk in general older population has not been available. This study aimed to create such a tool and examined its reliability and criterion-related validity.

Methods: 1,192 community elderly with a mean age of 74.7 (standard deviation, 5.8) years responded to a questionnaire consisting of 48 (Hatoyama) or 34 items (Kusatsu), which have been reported to be associated with nutritional state in older people. Item analysis was conducted on the 34 common items, and items were selected based on the following criteria: adequate pass rates and discriminative power, no gender and regional differences, and a certain level of commonality based on factor analysis. Next, the factor structure of the candidate items was examined through exploratory factor analysis, and confirmatory factor analysis was conducted as the final scale structure. Furthermore, Spearman’s partial rank correlation coefficients (sex- and age-adjusted) between the created index and important health indicators were examined to determine the criterion-related validity.

Results: Finally, we obtained a semantic coherence of four factors (named health beliefs, dietary status, physical activity, and food-related quality of life) totaling 13 items; confirmatory factor analysis of the four-factor solution yielded good model fit values, χ² (59) = 275.4 (P < 0.001), comparative fit index = 0.930, and root mean square error of approximation = 0.056. The factor loadings for each factor ranged from 0.43 to 0.82, indicating adequate loadings. The reliability of the index was shown to be high by Good-Poor analysis and Cronbach’s α. The index showed statistically significant correlations with all health indicators.

Conclusion: We have developed a simple assessment tool to evaluate early low nutrition risk in the general older population.

Introduction: This study aimed to determine the association between cumulative maternal physical activity level and their children’s physical activity in early childhood. We also compared the influence of each maternal physical activity on children’s physical activity in early childhood.

Methods: We analyzed the data from 1,067 Japanese mother-child pairs. Maternal physical activity was assessed using the International Physical Activity Questionnaire. Cumulative physical activity level in mothers was computed based on the categories (low, moderate, and high) of physical activity from five time points (pre-pregnancy, during pregnancy, 1.5, 3.5, and 5.5 years postpartum). Children’s physical activity level was measured at age 5.5 years using the WHO Health Behaviour School-aged Children questionnaire and defined as engaging in physical activity for at least 60 minutes per day for more than 5 days. Logistic regression analysis was used to determine the association between maternal and children’s physical activity levels.

Results: The results showed the positive association between cumulative maternal physical activity and children’s physical activity level (P for trend < 0.001). Furthermore, maternal physical activity during pregnancy (P for trend = 0.031) and 5.5 years postpartum (P for trend < 0.001) was positively associated with children’s physical activity.

Conclusion: A positive association was observed between the cumulative maternal physical activity level and the physical activity level of their children at 5.5 years of age. Furthermore, maternal physical activity during pregnancy and at 5.5 years postpartum were positively associated with the level of children’s physical activity.

Background: A recent systematic review showed Japan’s mortality from chronic obstructive pulmonary disease (COPD) is the lowest among 204 countries, despite notably higher smoking rates in men in Japan than in the United States. This study aims to compare (1) trends in smoking rates, (2) trends in COPD mortality, and (3) the spirometry-based COPD prevalence in the general adult population between Japan and the United States.

Methods: Age- and sex-specific smoking rates from the 1980s through 2010s and COPD mortality from 1999 through 2019 were obtained from national surveys and official statistics (International Classification of Diseases-10^th codes J40–44), respectively. A systematic review and meta-analysis was performed to estimate COPD prevalence in Japan, while the National Health and Nutrition Examination Survey 2007–2012 was used for the United States. A fixed ratio of 0.7 of forced expiratory volume in the first second of forced vital capacity was used to define COPD.

Results: Over the past 4 decades, men in Japan consistently had 20–30% higher smoking rates than their United States counterparts. From 1999–2019, age-adjusted COPD mortality in men in Japan was only a third of the United States, whereas that in women was less than a tenth in 2019. Synthesizing data from 11 studies, involving 89,955 participants, Japan’s COPD prevalence was more than 10% lower than in the United States in almost all age groups for both sexes.

Conclusion: This study showed markedly lower rates of COPD in Japan than in the United States. Investigating factors contributing to the paradoxical observations could lead to advancing COPD risk reduction strategies.

Background: The decline in measles vaccination coverage is a global concern. In Japan, coverage of the first dose of measles vaccine, which had exceeded the target of 95.0% since fiscal year (FY) 2010, fell to 93.5% in FY 2021. Vaccination coverage increased to 95.4% in FY 2022 but varied by municipality. Few studies have focused on regional disparities in measles vaccination coverage. This study aimed to clarify the regional disparities in measles vaccination coverage by municipality in Japan and their associated factors.

Methods: In this ecological study, the measles vaccination coverage in FY 2022; population density; area deprivation index (ADI; an indicator of socioeconomic status); proportion of foreign nationals, single-father households, single-mother households, and mothers aged ≥30 years; and number of medical facilities, pediatricians, and non-pediatric medical doctors in 1,698 municipalities were extracted from Japanese government statistics. Negative binomial regression was performed with the number of children vaccinated against measles as the dependent variable, number of children eligible for measles vaccination as the offset term, and other factors as independent variables.

Results: Vaccination coverage was less than 95.0% in 54.3% of municipalities. Vaccination coverage was significantly positively associated with population density and negatively associated with the proportion of single-father households, mothers aged ≥30 years, and the ADI (incidence rate ratios: 1.004, 0.976, 0.999, and 0.970, respectively).

Conclusion: This study showed regional disparities in measles vaccination coverage in Japan. Single-father households, age of mothers, and socioeconomic status may be key factors when municipalities consider strategies to improve vaccination coverage.