Objective: Trans fatty acid (TFA) intake raises public health concern owing to their potential adverse effects on health. Reduced intake is thus highly recommended. We aimed to identify indicators for selecting vegetable oils and margarines with low TFA contents by analyzing their association with fatty acid composition using machine learning.

Methods: TFA content and fatty acid composition in 32 vegetable oil and 28 margarine samples were measured using gas chromatography. Ridge regression and decision tree analyses were performed to predict and classify TFA content. For vegetable oils, fatty acid composition was used as the explanatory variable, and both fatty acid composition and lipid content were used for margarines.

Results: Respective average TFA contents in vegetable oils and margarines were 0.41 g/100 g and 0.43 g/100 g. Ridge regression was used to construct predictive models for TFAs in vegetable oils and margarines, revealing significant correlations between measured and predicted values. Decision tree analysis indicated that vegetable oils with less than 13% diene fatty acids, and margarines with less than 4.1% triene fatty acids can be classified as products with low TFA content.

Conclusions: These results suggest that vegetable oils with proportionally low diene fatty acid content and margarines with proportionally low triene fatty acid content tend to have low TFA contents.

Objective: This study aimed to examine the dietary behavior and knowledge that influence longitudinal changes in vegetable intake among remote island residents using existing health and nutrition survey data.

Methods: Data from health and nutrition surveys conducted in Nishinoshima town, a remote island in Shimane Prefecture, Japan, during the formulation of a health promotion plan (2014) and mid-term evaluation (2021) were used. The analysis included 135 men and women in their 20s~70s who responded to both surveys. Paired statistical tests were used to compare the characteristics and vegetable intake of the participants at two time points. Multiple regression analysis was used to examine the factors influencing the changes in vegetable intake between 2014 and 2021.

Results: Between 2014 and 2021, a significant reduction in vegetable intake was observed among men. Multiple regression analysis showed that change in "family composition (from living together to living alone)" was significantly associated with decreased vegetable intake, and increased "frequency of a well-balanced diet (combination of staple food, main, and side dishes)" was significantly associated with increased vegetable intake.

Conclusions: This study suggested that individual dietary behaviors and socioeconomic factors influenced changes in vegetable intake.

Objective: This study aimed to identify the optimal age to initiate meal preparation by examining its relationship with adult dietary habits.

Methods: Cross-sectional data were obtained from "The Survey of Attitude toward Shokuiku," conducted by the Japanese Ministry of Agriculture, Forestry and Fisheries in 2019. The responses of 1,721 Japanese individuals aged ≥ 20 years were analyzed. The participants were divided into three groups based on their current frequency of consuming a Japanese well-balanced diet; "almost daily," "4~5 days weekly," and "2~3 days weekly or less." Multinomial logistic regression analysis examined the relationship between all groups and the starting age for meal preparation in childhood (elementary school, junior high school, and 16~18 years).

Results: The well-balanced diet of 934 (56.4%), 323 (19.5%) and 398 (24.0%) participants were classified as "almost daily," "4~5 days weekly" and "2~3 days weekly or less," respectively. Compared to those who did not participate during childhood, for individuals who started meal preparation in "elementary school," the odds ratios (95% confidence interval) of consuming a well-balanced diet either "almost daily" or "4~5 days weekly" were 1.81 [1.37~2.39] and 1.72 [1.23~2.39], respectively. No association was found for "junior high school" or "16~18 years."

Conclusion: This study suggested that participation in meal preparation in elementary school promotes healthy eating in adulthood.

Objective: This study aimed to elucidate meal provision practices for patients under hotel quarantine during the seventh wave of COVID-19.

Methods: A nationwide questionnaire survey was conducted among the health departments of 47 prefectures, 87 cities with public health centers, and 23 special wards. The survey explored the process from meal procurement to delivery, meal content, and use of disaster-response frameworks.

Results: Responses were received from 88 local governments (response rate; 56.1%). Hotel quarantine was implemented in all prefectures and some ordinance-designated cities, totaling 34 local governments. The most frequently reported daily meal budget was "2,501~3,000 yen" (30.3%). Meals were primarily prepared by hotels (56.3%), with some flexibility in accommodating patient preferences and health conditions. Feedback regarding meal content included "many fried and greasy foods" (88.5%) and "strong flavor" (57.7%). Only 9.1% of the local governments used disaster support agreements or food stockpiles (n = 2 and n = 3, respectively).

Conclusion: Considerable variation was observed in meal budgets and allocation methods. Although some local governments offered foods and drinks to meet individual needs, patient feedback suggests that the nutritional content and quantity were sometimes inadequate for recovery. Disaster frameworks for nutritional assistance were rarely used.

Objective: Studies have indicated that replacing common milled rice with bran grind (BG) wash-free rice decreases serum phosphate levels in patients on hemodialysis. However, although BG wash-free rice can be cooked after washing, the effect of washing on phosphorus and potassium contents remains unclear. In this study, we aimed to evaluate the phosphorus and potassium contents in BG wash-free rice cooked either unwashed or after three washes.

Methods: BG wash-free rice and common milled rice, both produced in Kochi Prefecture in 2022 and 2023, were used. Common milled rice (washed three or ten times) and BG wash-free rice (unwashed or washed three times) were cooked following the Standard Tables of Food Composition in Japan, 2020 edition (8th revision). These are hereafter referred to as "common milled rice/washed rice 3," "common milled rice/washed rice 10," "BG wash-free rice/unwashed rice," and "BG wash-free rice/washed rice 3," respectively. After dry ashing, phosphorus and potassium contents were determined using the vanadomolybdate method and atomic absorption spectrophotometry, respectively.

Results: In uncooked rice, phosphorus and potassium contents were significantly lower in BG wash-free rice than in common milled rice; however, no significant difference was noted between BG wash-free rice/unwashed rice and common milled rice/washed rice 3. The phosphorus and potassium contents of BG wash-free rice/washed rice 3 were significantly lower than those of BG wash-free rice/unwashed rice and were comparable to those of common milled rice/washed rice 10.

Conclusion: These findings indicate that washing BG wash-free rice three times reduces its phosphorus and potassium contents.

Objective: To reduce health disparities, promoting a food environment that considers price and nutritional value is crucial. This study aimed to visualize low-priced, nutrient-rich fresh foods using a nutrient profiling model.

Methods: Nutrient values were obtained from Standard Tables of Food Composition in Japan (8th Revised Edition). Key nutrients to encourage included protein, dietary fiber, vitamins A, C, and E, calcium, iron, potassium, and magnesium, whereas saturated fat and sodium (salt equivalent) were limited. Food prices were sourced from a 2022 Retail Price Survey. Sixty-two fresh foods listed in both datasets were analyzed. Nutritional value was assessed using the nutrient-rich food model, and the relationship between price per 100 kcal and nutrient density was examined.

Results: Vegetables and tubers generally exhibited lower prices per 100 kcal and had higher nutritional value than fruits, meat, seafood, and eggs. Particularly, pumpkin, potato, and cabbage showed a favorable price-nutrition balance. Orange, mandarin orange, and persimmon showed similar favorable price-nutrition balances, whereas sardines and mackerel projected out among the animal-based foods.

Conclusions: This study identified affordable and nutrient-rich fresh foods. Although regular price updates are needed, the results suggest that applying this information to food selection and nutrition education may support a food environment that helps reduce health disparities related to economic factors.

Objective: This study investigated the combination of attitudes toward practicing a healthy diet and subjective diet-related quality of life (SDQOL) and their association with the frequency of having a healthy diet, subjective health, and body mass index (BMI).

Methods: Data were obtained from 1,000 workers aged 20~64 years living in Tokyo, using an online research platform. Participants were categorized into four groups based on their attitudes toward practicing a healthy diet and SDQOL; no healthy diet and low SDQOL, no healthy diet and high SDQOL, healthy diet and low SDQOL, and healthy diet and high SDQOL. Associations between these groups and demographics were examined using the Chi-square test. Binomial logistic regression models examined the frequency of having a healthy diet. Multinomial logistic regression analysis examined subjective health and BMI.

Results: The healthy diet and high SDQOL group mostly comprised women, cohabitate, and who had an annual household income of ≥6 million yen. Compared to the no healthy diet and low SDQOL group, the healthy diet and high SDQOL group had a healthy diet daily (odds ratio [95% confidence interval]; 2.41 [1.54~3.79]), more likely to have good subjective health (7.83 [4.42~13.9]), and less likely to be underweight (0.49 [0.27~0.88]) or obese (0.45 [0.27~0.76]).

Conclusion: Individuals with attitude toward practicing a healthy diet and high SDQOL had a higher frequency of having a healthy diet, suggesting that they had subjective health and appropriate body weight.