This cross-sectional study investigated the association between eating alone at each meal and health status, including functional capacity among community-dwelling Japanese elderly living with others. A self-administered questionnaire was mailed to all 8004 residents aged 65 or older, residing in the same Japanese town in March 2016. Eating alone was assessed by first asking whether participants ate three separate meals each day (i.e., breakfast, lunch, and dinner), and those who answered affirmatively were then asked how many people were usually present at each meal. Health status was assessed in terms of subjective health, medical history, care needs, body mass index, depression, and functional capacity. Data from 2809 respondents were analyzed. Those who reported not being in good subjective health and a history of hypertension were significantly more likely to eat alone at breakfast (odds ratio 1.27; 95% confidence interval 1.01–1.61, and 1.26; 1.06–1.49). Depressive symptoms and many subscales of functional capacity were also significantly associated with eating alone at breakfast, lunch, and dinner (p < 0.05). Many health status indicators were related to eating alone at each meal, especially breakfast.

This study aimed to reveal the influence of food production experience on dietary knowledge, dietary awareness, dietary behaviors, and health among Japanese populations. We conducted a systematic review of articles published between January 2000 and September 2018 (PROSPERO registration number: CRD42019117163) using the following four databases: PubMed, Web of Science, CiNii, and ICHUSHI. The search formulas were created by combining search terms “agricultural experience,” “garden,” “diet,” “food,” “physical activity,” “health,” and “well-being.” The articles were identified by titles, abstracts, and whole texts. We evaluated the content of the articles that met the adoption criteria. We included original articles from peer-reviewed scientific journals, articles written in Japanese or English, observational or interventional studies with statistical analyses, and articles targeting general Japanese people (except for those targeting patients or disabled) to examine the relationship according to the purpose of this review. Nineteen articles met the study criteria, including 10 cross-sectional studies, one retrospective study, seven pre–post studies, and three non-randomized controlled trials. Two studies combined multiple research designs. Thus, food production experiences were suggested to have a positive influence on dietary knowledge, dietary awareness, food preference, dietary behaviors, and mental health among the Japanese. However, the overall quality of the included studies was low. Further verification with randomized controlled trials and prospective cohort studies is required.

Background/Objectives: Low masticatory function has been proposed as a risk factor for sarcopenia. This study investigated its potential association with body composition and physical performance in community-dwelling older adults. Methods: Participants included adults aged ≥65 years (643 men; 797 women) who volunteered for a longitudinal cohort study. Masticatory function was objectively assessed using gummy jelly and subjectively evaluated via a structured questionnaire. The skeletal muscle mass, body mass index, waist circumference, handgrip strength, gait speed, and five-time chair-stand test were assessed. Results: Objectively measured masticatory function was classified as low (12.6%), moderate (38.0%), or high (49.4%). In men, masticatory function was significantly associated with skeletal muscle mass index (low, moderate, and high: 7.4, 7.7, and 7.7 kg/m²; p = 0.005), handgrip strength (31.8, 34.2, and 35.5 kg; p < 0.001), and gait speed (1.3, 1.4, and 1.4 m/s; p = 0.003). In women, low masticatory function was linked to a higher body mass index (22.9, 22.0, and 21.9 kg/m²; p = 0.028) and waist circumference (82.9, 80.8, and 80.4 cm; p = 0.041). Moreover, these significant associations persisted after adjusting for covariates. Discrepancies were observed between objective and subjective measures of masticatory function, with approximately 40% of participants showing low objective masticatory function, perceiving their chewing ability as normal. Subjective masticatory function exhibited no significant associations with anthropometric measures or sarcopenia components. Conclusions: In men, objectively measured low masticatory function was associated with reduced skeletal muscle mass and poor physical performance; in women, it was linked to higher body mass index.

The aim of this cross-sectional study was to examine the number of days required to estimate habitual vegetable variety by conducting a multiday, dietary record. Sixty respondents from three groups in Japan (rural residents, general students, and nutrition students) participated in the study using a self-administered questionnaire in September 2018. To measure vegetable variety, the number of different vegetables consumed was extracted from the dietary records of seven consecutive days. Differences in the number of vegetables consumed and the capture proportion over seven consecutive days between groups were examined using repeated measures analysis of variance and one-way analysis of variance. The vegetable variety between each day was also compared using Pearson’s correlation coefficient. The vegetable variety based on dietary records for seven consecutive days confirmed the differences between groups by repeated measurements (p = 0.013). However, there was no significant difference among groups in the capture proportion per survey day based on seven consecutive days. Furthermore, there were significant correlations between the number of vegetables consumed over seven consecutive days and that consumed on two or more days (r > 0.50, p < 0.01) and especially three or more days in all groups (r > 0.70, p < 0.001). The present study suggested that a dietary survey over two or more days could provide an estimate of habitual vegetable variety.

This cross-sectional study examined the association between cooking frequency and nutrient and food group intake among female university students with different living arrangements in Japan. Nutrient and food group intakes were assessed using a validated, brief, self-administered diet history questionnaire. Cooking frequency was measured using a single question on a five-point scale. The questionnaire also asked about living arrangements. Of the 91 respondents, 75 females were analyzed. Regarding cooking frequency, cooking at least 1–2 days a week was classified as cooking, and the “cooking yet living with families” group was compared with the “not cooking and living with families” and “cooking and living alone” groups. Based on the intakes of the “cooking yet living with families” group, the “not cooking and living with families” group consumed more total fat (29.5% energy vs. 33.0% energy, p = 0.010) and fewer cereals (224.8 g/1000 kcal vs. 179.6 g/1000 kcal, p = 0.007), and the “cooking and living alone” group consumed more confectionaries (21.0 g/1000 kcal vs. 34.5 g/1000 kcal, p = 0.023). This study showed that female university students who cook at least once a week and live with their families may have better diet quality than those who do not cook and live with their families and those who cook and live alone.

Background: Previous studies have reported that vegetable variety reduces the risk for noncommunicable diseases independent of the amount consumed. Objective: This study aimed to examine and compare the validity and reproducibility of several scales to determine vegetable variety. Methods: In total, 23 nutrition students in Japan reported their vegetable intake over the past month using a self-administered questionnaire between July and August 2021. Specifically, four scales were used: (1) a single question regarding the number of vegetables consumed (scale A); (2) a scale containing 9 vegetable subgroups included in the brief-type self-administered diet history questionnaire (scale B); (3) a scale containing 19 vegetable items included in a self-administered diet history questionnaire (scale C); and (4) a scale containing 20 vegetable items from the Ranking of Vegetable Consumers in Japan, which was analyzed based on a report on the National Health and Nutrition Survey in Japan (scale D). Scale validity was assessed by correlation with the number of vegetables consumed, which was collected from dietary records for 7 consecutive days. Reproducibility was assessed by test-retest reliability. Results: Regarding the validity of the 4 scales, significant correlations were found between scales C (ρ=0.51) and D (ρ=0.44) with vegetable variety based on dietary records, but scales A (ρ=0.28) and B (ρ=0.22) were not significantly correlated. Reproducibility showed a significant correlation in scale B (ρ=0.45) and strong correlations in scales C (ρ=0.73) and D (ρ=0.75). Conclusions: The scales for vegetable items have acceptable validity and reproducibility compared to the scales that used a single question or vegetable subgroup and, therefore, may determine the variety of vegetables consumed.