Association between meal context and meal quality: an ecological momentary assessment in Japanese adults.

PURPOSE: The purpose was to assess the relationship between the quality of meals and its context. METHODS: We conducted a cross-sectional study of 222 Japanese adults aged 30-76 years in 2021. The following information was obtained from the 4-d weighed dietary records: the recording day (working or not), meal type (breakfast, lunch, or dinner), eating companions (alone or with someone), eating location (at home or away from home), and screen-based activity (yes or no). The nutritional quality of each meal was evaluated using the Healthy Eating Index 2020 (HEI-2020). RESULTS: The analysis included 1,295 meals for males and 1,317 for females. The mean HEI-2020 ranged from 43.0 (lunch) to 51.9 (dinner) in males and from 45.7 (breakfast) to 52.0 (dinner) in females. Multilevel linear regression showed that, in males, lunch had a significantly lower HEI-2020 score compared to breakfast (ß = -1.81, 95% confidence interval [CI]: -3.42, - 0.20), while dinner had a significantly higher HEI-2020 score (ß = 6.77, 95% CI: 5.34, 8.20). Eating with someone was significantly associated with a higher HEI-2020 score (ß = 2.22, 95% CI: 0.76, 3.67). Among females, dinner had a higher HEI-2020 score than breakfast (ß = 5.21, 95% CI: 3.72, 6.70). Eating away from home was associated with higher HEI-2020 scores (ß = 2.14, 95% CI: 0.04, 4.24). CONCLUSION: Meal type, location, and eating companions were associated with meal quality in this population, with differences between males and females. Incorporating these factors in nutrition education and interventions can enhance diet quality.

Validity and Reproducibility of a Food Frequency Questionnaire for Dietary Assessment in Japanese People.

A 76-item food frequency questionnaire (FFQ) was developed to investigate nutritional epidemiology in urban residents in Japan. The authors prepared two food models-a life-size three-dimensional model and a life-size two-dimensional photograph-to assess the FFQ portion size. The validity of the FFQ was verified using the two food models by comparing them with 16-d weighted dietary records (WDRs). Validation was conducted by comparing the FFQ1 findings with those obtained with the WDR, which is regarded as the gold standard, and reproducibility was verified by comparing the findings from FFQ2 and FFQ1. After completion of the WDR, the participants were randomized into two groups. In one group, the FFQ was conducted using life-size three-dimensional models (3D-FFQ) to estimate the portion size. In the other group, the FFQ was administered using life-size photo collection (2D-FFQ). Regarding validity, the median values (range) of Pearson's correlation coefficients for the energy and nutrient intake of the 32 items by the WDR and FFQ1 were r=0.53 (0.30-0.68) in the 3D-FFQ and r=0.57 (0.33-0.87) in the 2D-FFQ. When FFQs with 2D or 3D food models and two different portion sizes were compared with regard to the intake of certain food groups, energy, and nutrients, both the 2D-FFQ and 3D-FFQ provided good correlation coefficients with the WDR.

Dietary Amino Acid Composition and Glycemic Biomarkers in Japanese Adolescents.

Protein intake reportedly increases the risk of diabetes; however, the results have been inconsistent. Diabetes in adulthood may be attributed to early life dietary amino acid composition. This study aimed to investigate the association between amino acid composition and glycemic biomarkers in adolescents. Dietary intake was assessed using a food frequency questionnaire, and fasting glucose and insulin levels were measured in 1238 eighth graders. The homeostatic model assessment (HOMA) indices (insulin resistance and ß-cell function) were calculated. Anthropometrics were measured and other covariates were obtained from a questionnaire. Amino acid composition was isometric log transformed according to the compositional data analysis, which was used as explanatory variables in multivariate linear regression models for glucose, insulin, and HOMA indices. Only the association between glucose and leucine was significant. In replacement of other amino acids with leucine, an increase of 0.1% of total amino acids correlated with a lower glucose level (-1.02 mg/dL). One-to-one substitution of leucine for isoleucine or methionine decreased glucose (-2.98 and -2.28 mg/dL, respectively). Associations with other biomarkers were not observed. In conclusion, compositional data analysis of amino acids revealed an association only with glucose in adolescents; however, the results of this study should be verified in other populations.

[Actual usage of Dietary Reference Intakes for Japanese among individuals engaged in work related to food and nutrition: Comparison between workplaces].

Objective　The aim of this study was to compare how Dietary Reference Intakes for the Japanese (DRIs), which are dietary guidelines proposing reference values for the intake of energy and nutrients by healthy Japanese people, are used by personnel whose work involves diet, food, or nutrition.Methods　A web-based questionnaire survey was conducted in July 2023 among those involved in work closely related to diet, food and/or nutrition. The frequency of the use of DRIs in daily work and the details of use, including the chapter used, difficulty of use, information source for revisions, and interest in a revised version, were compared among workplaces (e.g., medical institutions; school and welfare facilities; government institutions; dietitian training schools; companies; and freelancer in community and others).Results　Among 1,030 participants, 58% (n=597) used DRIs "very often" or "often" in their daily work. For example, DRIs were used to prepare institutional meals and facilitate nutrition management and guidance in medical institutions; prepare institutional meals in schools and welfare facilities; ensure nutrition management and guidance for citizens and prepare courses/materials for government institutions; and prepare courses/materials for dietitian training schools. Regarding the main parts of the DRIs used, most respondents chose the chapters entitled "Energy" (66%) and "Macronutrients" (72%). For all participants (n=1,030), the main difficulties in the use of DRIs were "a large number of sentences in the DRIs and an insufficient time to read" (stated by 54% of all respondents; the proportion did not significantly differ among workplaces). The main source of information on revised DRIs was "seminars and workshops by the Japan Dietetic Association" (70% of all respondents). However, many respondents in the government and dietitian training institutions also identified "workshops or public information by the Ministry of Health, Labour and Welfare" as major sources. Regarding participants' main interest in the revised version of the DRIs, general policy (77%) and revised reference values (74%) generated the highest levels of interest. Those working at dietitian training schools had a greater interest in change related to scientific evidence for each reference value than those working elsewhere.Conclusions　DRIs are frequently used by those involved in work related to food and nutrition. In this study, DRI use and related interests differed based on the workplaces surveyed. In future revisions of DRIs, the addition of further descriptions or appendices in line with their use in workplaces may be needed.

Nut consumption during pregnancy is associated with decreased risk of peer problems in 5-year-old Japanese children.

OBJECTIVES: Nuts are nutrient-dense foods rich in unsaturated fatty acids, protein, dietary fiber, vitamins, and minerals. The present prebirth cohort study examined the association between maternal nut intake during pregnancy and the risk of childhood behavioral problems in 5-year-old Japanese children. METHODS: Study subjects were 1199 mother-child pairs. Dietary intake was assessed using a diet history questionnaire. Emotional problems, conduct problems, hyperactivity problems, peer problems, and low prosocial behavior were assessed using the parent-reported version of the Strengths and Difficulties Questionnaire. Adjustments were made for a priori-selected nondietary confounders and potentially related dietary factors. RESULTS: Compared with mothers who had not eaten nuts during pregnancy, mothers who had eaten nuts had a significantly reduced risk of peer problems in children; the adjusted odds ratio was 0.64 (95% confidence interval: 0.42-0.97). There were no measurable associations between maternal consumption of nuts during pregnancy and the risk of childhood emotional problems, conduct problems, hyperactivity problems, and low prosocial behavior. CONCLUSIONS: Maternal consumption of nuts during pregnancy may be associated with a decreased risk of peer problems in 5-year-old children.

AI-based Apoptosis Cell Classification Using Phase-contrast Images of K562 Cells.

BACKGROUND/AIM: This study aimed to automate the classification of cells, particularly in identifying apoptosis, using artificial intelligence (AI) in conjunction with phase-contrast microscopy. The objective was to reduce reliance on manual observation, which is often time-consuming and subject to human error. MATERIALS AND METHODS: K562 cells were used as a model system and apoptosis was induced following administration of gamma-secretase inhibitors. Fluorescence staining was applied to detect DNA fragmentation and caspase activity. Cell images were obtained using both phase-contrast and fluorescence microscopy. Two AI models, Lobe(R) and a server-based ResNet50, were trained using these images and evaluated using F-values through five-fold cross-validation. RESULTS: Both AI models demonstrated effectively categorized individual cells into three groups: caspase-negative/no DNA fragmentation, caspase-positive/no DNA fragmentation, and caspase-positive/DNA fragmentation. Notably, the AI models' ability to differentiate cells relied on subtle variations in phase-contrast images, potentially linked to changes in refractive indices during apoptosis progression. Both AI models exhibited high accuracy, with the server-based ResNet50 model showing improved performance through repeated training. CONCLUSION: This study demonstrates the potential of AI-assisted phase-contrast microscopy as a powerful tool for automating cell classification, especially in the context of apoptosis research and the discovery of anticancer substances. By reducing the need for manual labor and enhancing classification accuracy, this approach holds promise for expediting high-throughput cell screening, significantly contributing to advancements in medical diagnostics and drug development.

Factors Associated with Anemia and Iron Deficiency during Pregnancy: A Prospective Observational Study in Japan.

Gestational anemia (GA) is a global health concern with a remarkably high prevalence in Japan, which is associated with various maternal and neonatal outcomes. This study aimed to explore whether GA and non-anemic iron deficiency (NAID) during the third trimester is associated with maternal characteristics, nutrient intake, low birth weight (LBW), and preterm birth. Participants were categorized into GA, NAID, and normal groups, based on serum ferritin and hemoglobin levels. Nutrient intake was assessed using the Brief Diet History Questionnaire. Data from 317 pregnant women were analyzed, including 110 (34.7%), 151 (47.6%), and 56 (17.6%) women in the GA, NAID, and normal groups, respectively. Factors associated with GA included being multipara (p < 0.001) and not taking any type of iron supplements in the third trimester (p = 0.043). The normal group had a significantly higher proportion of preterm birth and LBW than the GA and NAID groups. The GA group had a significantly higher energy intake than the normal group (p = 0.044). Overall, energy and micronutrient intake were significantly below the estimated average requirement in the dietary reference intakes for Japanese. Health care professionals need to consider nutritional advice that can prevent GA by focusing on overall micronutrients, not just energy intake.

Identification and estimation of the intake of fermented foods and their contribution to energy and nutrients among Japanese adults.

OBJECTIVE: Few studies have reported intakes of fermented foods with their clear definitions. This study aimed to identify fermented foods and beverages consumed in Japan based on international definitions and to estimate their intake and contribution to energy and nutrients. DESIGN: Data from a 16-days (four 4 non-consecutive days within each season at 3-month intervals) semi-weighted dietary record (DR) was used. To identify "entirely fermented foods" and "partially fermented foods", a literature search on food processing and ingredients was conducted for all foods that appeared in the DR. For "partially fermented foods", only the weight of the fermented food component was included in the estimation of total fermented food intake. SETTING: Four regions in Japan: Osaka, Nagano, Tottori, and Okinawa. PARTICIPANTS: Two-hundred forty-two apparently healthy Japanese adults aged 31-81 years. RESULTS: Of the 1,396 kinds of unique foods that appeared in the DR, 101 were "entirely fermented foods" and 104 were "partially fermented foods". The mean intake of fermented foods was 438 g/day per person (17% of the total weight). They were mainly derived from beer, coffee, bread, and yogurt. The mean contribution of fermented foods to the total energy intake was 18%. For nutrients, the contribution to total intake was high to sodium (46%), magnesium (22%), and calcium (20%). CONCLUSIONS: Fermented foods account for approximately one-fifth of the total weight and energy of dietary intake, and are important contributors to some nutrients in Japanese adults.

A scoping review of dietary assessment questionnaires potentially suitable for assessing habitual dietary intake in the National Health and Nutrition Survey, Japan.

This scoping review aimed to identify questionnaire-based dietary assessment methods for use in the National Health and Nutrition Survey (NHNS) in Japan. The search was conducted in three databases (PubMed, Web of Science, and Ichushi) to identify questionnaire such as food frequency questionnaire and dietary history questionnaire validated against dietary recalls or food records for the intakes of both food groups and nutrients among Japanese adults. Study quality was assessed based on previously developed criteria. We extracted the questionnaire characteristics and the design and results of the validation studies. We identified 11 questionnaires, with the number of food items ranging from 40 to 196, from 32 articles of good quality. In the validation studies, participants were aged 30-76 years and 90% of the articles used ≥3 d dietary records as reference. The number of nutrients and food groups with a group-level intake difference within 20% against the reference method ranged from 1 to 30 and 1 to 11, respectively. The range of mean correlation coefficients between questionnaire and reference methods were 0.35-0.57 for nutrients and 0.28-0.52 for food groups. When selecting a survey instrument in the NHNS from the 11 existing questionnaires identified in this study, it is important to select one with high group-level comparison and correlation coefficient values on the intended assessment items after scrutinizing the design and results of the validation study. This review may serve as a reference for future studies that explore dietary assessment tools used for assessing dietary intake in specific representative populations.

Association of disaster-related damage with inflammatory diet among older survivors of the Great East Japan Earthquake and Tsunami.

Traumatic experiences from disasters have enduring effects on health, both directly and indirectly by influencing health behaviours. Among potential pathways, the impact of disaster-related trauma on dietary patterns has been understudied. This study investigated the relationship between disaster-related trauma and dietary inflammatory index (DII®), and how these relationships differed by gender and whether they prepare meal by themselves or not among older survivors of the 2011 Great East Japan Earthquake and Tsunami (n 1375). Dietary data were collected in 2020 using a brief-type self-administered diet history questionnaire, from which we derived a dietary inflammatory index (DII®) based on twenty-six food/nutrient items, where higher scores indicate pro-inflammatory (i.e. unhealthy) diet. We found that the experience of housing damage due to the earthquake and tsunami was associated with slightly higher DII scores (coef. = 0·38, 95 % CI -0·05, 0·81). Specifically, women who cooked by themselves tended to have higher DII when they experienced housing damage (coef. = 1·33, 95 %CI -0·63, 3·28). On the other hand, loss of friends was associated with a lower DII score (coef. = -0·28, 95 % CI -0·54, -0·01). These findings highlight the importance of providing support to groups who are at increased risk of deterioration in dietary quality in the aftermath of disasters.

Effect of overweight/obesity and metabolic syndrome on frailty in middle-aged and older Japanese adults.

Background: The potential for developing frailty exists in middle-aged and older adults. While obesity and metabolic syndrome (MetS) increase the risk of frailty in older adults, this relationship remains unclear in middle-aged adults, who are prone to developing lifestyle-related diseases. Objective: To examine the effect of overweight/obesity and MetS on frailty development in middle-aged and older Japanese adults using real-world data. Methods: This nationwide cohort study used exhaustive health insurance claims data of 3,958,708 Japanese people from 2015 to 2019 provided by the Japan Health Insurance Association. Participants aged ≥35 and < 70 years who received health checkups in 2015 were included. Multivariate logistic regression was used to assess the effect of body mass index (BMI) and MetS or MetS components (i.e., diabetes, hypertension, and dyslipidemia) in 2015 on frailty risk assessed using the hospital frailty risk score in 2019. Additionally, a subgroup analysis was performed to examine the interaction effects of MetS components and 4-year weight change (%) on frailty risk among participants who were overweight and obese (BMI ≥25 kg/m2). Results: In 2019, 7204 (0.2%) and 253,671 (6.4%) participants were at high and intermediate frailty risks, respectively. Obesity and MetS were independently associated with intermediate/high frailty risk (odds ratio (OR) 1.36, p < 0.05; OR 1.23, p < 0.05, respectively) and high frailty risk (OR 1.80, p < 0.05; OR 1.37, p < 0.05, respectively) in all participants. Although all MetS components were frailty risk factors, these effects diminished with age in both sexes. Subgroup analysis of patients with diabetes revealed that 5%-10% weight loss was associated with reduced frailty risk in both sexes. Conclusions: Obesity, MetS, and MetS components were independent frailty risk factors in middle-aged and older Japanese adults. Weight loss of up to 10% over 4 years prevented frailty in patients with diabetes who were overweight and obese.

The association of highly processed food consumption with food choice values and food literacy in Japanese adults: a nationwide cross-sectional study.

BACKGROUND: Highly processed food (HPF) consumption is increasing globally and has become a prominent public health concern. However, the relationship between HPF consumption and food choice values and food literacy is unknown. This study aimed to examine the association of HPF consumption with food choice values and food literacy. METHODS: This cross-sectional study used data from a nationwide questionnaire survey conducted in 2018 among 2232 Japanese adults aged 18-80 years. We assessed eight food choice values (accessibility, convenience, health/weight control, tradition, sensory appeal, organic, comfort, and safety) using a 25-item scale, and food literacy characterised by nutrition knowledge (using a validated 143-item questionnaire), cooking and food skills (using 14- and 19-item scales, respectively), and eight eating behaviours (hunger, food responsiveness, emotional overeating, enjoyment of food, satiety responsiveness, emotional undereating, food fussiness, and slowness in eating, using the 35-item Adult Eating Behavior Questionnaire). HPF consumption was estimated using a validated brief diet history questionnaire. The associations between HPF consumption and age, body mass index, energy intake, and each score on food choice values and food literacy were evaluated by multiple linear regression. RESULTS: In males, one standard deviation increase in scores for cooking skill and satiety responsiveness was associated with an increase in HPF consumption by 22.1 g/4184 kJ (95% confidence interval (CI): 6.6 to 37.5) and 15.4 g/4184 kJ (95% CI: 6.0 to 24.7), respectively. In females, one standard deviation increase in age and scores for safety and nutrition knowledge corresponded to a decrease in HPF consumption by - 16.4 g/4184 kJ (95% CI: - 23.4 to - 9.3), - 9.9 g/4184 kJ (95% CI: - 19.1 to - 0.7), and - 11.1 g/4184 kJ (95% CI: - 17.0 to - 5.3), whereas one standard deviation increase in the satiety responsiveness score corresponded to an increase in HPF consumption by 13.1 g/4184 kJ (95% CI: 6.8 to 19.4). CONCLUSIONS: This cross-sectional study suggests that several aspects of food choice values and food literacy were associated with HPF consumption in Japanese adults. Further studies are needed to confirm our findings in a broader context.

Usual Nutrient Intake Distribution and Prevalence of Nutrient Intake Inadequacy among Japanese Children and Adults: A Nationwide Study Based on 8-Day Dietary Records.

In this cross-sectional study, we evaluated nutrient intake adequacy in 4450 Japanese people aged 1-79 years. Dietary data was collected through non-consecutive 8-day weighed dietary records. Usual nutrient intakes from foods and beverages were estimated using the Multiple Source Method. Participant proportions with intakes below and above the Japanese Dietary Reference Intakes (2020) were calculated. Usual intakes of most nutrients were below the Estimated Average Requirement; calcium showed a high percentage of inadequacy across all sex and age groups (29-88%), and iron showed a high inadequacy among females aged 12-64 years (79-95%). The percentages of energy from protein and carbohydrates, dietary fibre, and potassium were typically below the lower limit of the Tentative Dietary Goal for Preventing Lifestyle-related Diseases (DG). Furthermore, over 20% of the participants exceeded the upper limit of the DG for the percentages of energy from total and saturated fats, and over 88% exceeded the upper limit of the DG for sodium. Japanese children and adults could improve their nutrient intake by increasing calcium, iron, dietary fibre, and potassium and reducing total and saturated fats and sodium. These findings can inform policies and interventions to improve nutrient intake in Japan.

Association of serum docosahexaenoic acid and eicosapentaenoic acid levels with dietary intakes and supplement use during pregnancy: a prospective observational study.

This study aimed to determine the association of serum docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA) levels with dietary intakes and supplement use during pregnancy. This prospective observational study was conducted at a university hospital in Tokyo, Japan. Participants in their second and third trimesters were given a self-administered questionnaire assessing the frequency of DHA and EPA supplement use in the past month and a brief-type self-administered diet history questionnaire. Non-fasting serum DHA and EPA levels were analysed using gas chromatography. Differences in biomarkers by frequency of supplement use were determined using multiple comparison analyses, and Spearman's correlation coefficient was used to determine biomarkers and DHA and EPA intakes by food group. Of the 116 participants, 11 (9⋅5 %) in the second trimester and 18 (15⋅5 %) in the third trimester regularly used supplements (≥5 times per week). Regular users had higher serum DHA and EPA levels than never users in the second and third trimesters. Dietary DHA and EPA intake from fish and shellfish was positively correlated with serum DHA and EPA in the second and third trimesters. Supplement use ≥5 times per week and fish and shellfish intake were associated with high serum DHA and EPA levels.

Intake levels and main sources of nutrients for Japanese children with motor or intellectual disabilities.

Proper nutritional management is important for the growth and development of children with motor or intellectual disabilities; however, few studies have investigated the nutrient intake of children with disabilities. This study aimed to investigate the nutrient intake and food groups that are the main sources of nutrients for children with disabilities. This cross-sectional observational study included twenty-five children (mean age, 11⋅8 years) from five hospitals in Japan. Using a 3-d weighed dietary record, we estimated the daily nutrient intake and food and beverage sources that contributed to nutrient intake. The mean values of calcium, magnesium, iron, vitamin A, thiamine, riboflavin, and vitamin C intake were below the recommended dietary allowance, and those of dietary fiber and potassium were below the levels recommended by the Tentative Dietary Goal for Preventing Lifestyle-related Diseases (DG). In contrast, the mean intake values of fat, saturated fatty acids, and sodium were above the DG levels. Dairy products, meat, vegetables, and cereals were found to be the major contributors of nutrients. Increased intake of vegetables may help alleviate insufficient micronutrient intake in children with disabilities.

National Nutrition Surveys Applying Dietary Records or 24-h Dietary Recalls with Questionnaires: A Scoping Review.

Development of an accurate and efficient dietary method is required for national nutrition surveys. Some countries conduct dietary surveys and combine 24-h dietary records or 24-h dietary recalls with dietary questionnaires. This scoping review aimed to summarize studies that used results from national surveys that combined detailed dietary surveys (dietary records or 24-h dietary recall) and dietary questionnaires and identify the purpose of combining the two methods. The PubMed database and manual searches were used for the literature review. We extracted 58 articles from 16 national nutrition surveys from 14 countries. Most studies used 24-h dietary recall for detailed dietary surveys and the food frequency questionnaire (FFQ) or food propensity questionnaire (FPQ) for questionnaire surveys. Among 37 studies from eight countries, the purpose of combining the two dietary survey methods was to estimate energy and nutrient intakes from detailed dietary surveys and habitual food intake from questionnaires. These findings are useful as a reference when introducing new dietary survey methods in future national nutrition surveys.

Association of Eicosapentaenoic and Docosahexaenoic Acid Intake with Low Birth Weight in the Second Trimester: The Japan Pregnancy Eating and Activity Cohort Study.

This study examined the association of eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) intake during the second trimester with low birth weight (LBW) in pregnant Japanese women and was conducted in conjunction with the Japan Pregnancy Eating and Activity Cohort (J-PEACH) study. The study included 504 pregnant women from four Japanese sites. During the second trimester (14-27 weeks), the participants filled out a self-administered questionnaire assessing the frequency of DHA and EPA supplement intake in the past month, as well as a brief-type self-administered diet history questionnaire (BDHQ). The analysis involved data from two time points: responses to the BDHQ and infant data at birth. In total, 471 and 33 participants were classified into the normal birth weight and LBW groups, respectively. The participants were divided into high-, medium-, and low-intake groups based on their total dietary and EPA and DHA supplementary intakes. The Cochran-Armitage trend test was used to analyze the data; the prevalence of LBW was higher in the low-intake group (p = 0.04). There was no significant sex-based trend (p = 0.27 and p = 0.35). In Japanese women, low dietary and supplementary EPA and DHA intake until the second trimester were risk factors for LBW.

Are popular books about diet and health written based on scientific evidence? A comparison of citations between the USA and Japan.

OBJECTIVES: To describe and compare the references cited in popular books about diet and health between the USA and Japan. DESIGN: Books were selected based on their best-seller rankings in the diet and health category of online bookstores. We identified references throughout all pages of the books and examined the number of references, reference format (identifiable or not) and presence of specific types of references, such as systematic reviews of human research. We compared the characteristics of references between the two countries and examined related factors to citation. SETTING: Cross-sectional study. PARTICIPANTS: Books (n 100 in each country). RESULTS: Among 100 books from each country, sixty-five US and sixty-six Japanese books had references. Forty-five US books cited more than 100 references, against only five Japanese books. The number of books that cited systematic reviews of human research differed between the USA (n 49) and Japan (n 9). Additionally, the number of books that provided identifiable information for all references was significantly higher in the USA (n 63) than in Japan (n 42). Books whose first authors have licences of medical doctors were more likely to cite references than those without in both countries. CONCLUSIONS: Two-thirds of books about diet and health cited references in both the USA and Japan, but Japanese books cited fewer references and were less likely to cite systematic reviews and provide identifiable references than US books. Further research into the scientific reliability of information in books about diet and health is warranted.

Web-Based Content on Diet and Nutrition Written in Japanese: Infodemiology Study Based on Google Trends and Google Search.

BACKGROUND: The increased availability of content of uncertain integrity obtained through the internet is a major concern. To date, however, there has been no comprehensive scrutiny of the fitness-for-purpose of web-based content on diet and nutrition. OBJECTIVE: This cross-sectional study aims to describe diet- and nutrition-related web-based content written in Japanese, identified via a systematic extraction strategy using Google Trends and Google Search. METHODS: We first identified keywords relevant for extracting web-based content (eg, blogs) on diet and nutrition written in Japanese using Google Trends. This process included identification of 638 seed terms, identification of approximately 1500 pairs of related queries (top) and search terms, the top 10% of which were extracted to identify 160 relevant pairs of related queries (top) and search terms, and identification of 107 keywords for search. We then extracted relevant web-based content using Google Search. RESULTS: The content (N=1703) examined here was extracted following a search based on 107 keywords. The most common themes included food and beverages (390/1703, 22.9%), weight management (366/1703, 21.49%), health benefits (261/1703, 15.33%), and healthy eating (235/1703, 13.8%). The main disseminators were information technology companies and mass media (474/1703, 27.83%), food manufacturers (246/1703, 14.45%), other (236/1703, 13.86%), and medical institutions (214/1703, 12.57%). Less than half of the content (790/1703, 46.39%) clearly indicated the involvement of editors or writers. More than half of the content (983/1703, 57.72%) was accompanied by one or more types of advertisement. The proportion of content with any type of citation reference was 40.05% (682/1703). The themes and disseminators of content were significantly associated with the involvement of editors or writers, accompaniment with advertisement, and citation of reference. In particular, content focusing on weight management was more likely to clearly indicate the involvement of editors or writers (212/366, 57.9%) and to be accompanied by advertisement (273/366, 74.6%), but less likely to have references cited (128/366, 35%). Content from medical institutions was less likely to have citation references (62/214, 29%). CONCLUSIONS: This study highlights concerns regarding the authorship, conflicts of interest (advertising), and the scientific credibility of web-based diet- and nutrition-related information written in Japanese. Nutrition professionals and experts should take these findings seriously because exposure to nutritional information that lacks context or seems contradictory can lead to confusion and backlash among consumers. However, more research is needed to draw firm conclusions about the accuracy and quality of web-based diet- and nutrition-related content and whether similar results can be obtained in other major mass media or social media outlets and even other languages.

Association between dietary pattern and insomnia symptoms among independent older adults: A cross-sectional study based on JAGES.

BACKGROUND: Poor diet can cause sleep disorders; however, this association has not been established in older populations. This study investigated the association between dietary patterns and insomnia symptoms in independent older adults. METHODS: This cross-sectional study targeted independent older Japanese adults aged ≥74 years. We used insomnia symptoms classified into three domains: difficulty initiating sleep (DIS), difficulty maintaining sleep (DMS), and insomnia. These symptoms were assessed as dependent variables by a self-reported questionnaire. Dietary patterns (DP), identified by principal component analysis of a self-administered diet history questionnaire, were used as independent variables. Poisson regression analysis was used to estimate the prevalence ratios and 95% confidence intervals with adjustment for potential confounders. RESULTS: Among 1,311 participants (mean age = 80.1; women, 48.5%), we identified three dietary patterns: DP1 was characterized by a high intake of vegetables, soy products, and fruits and a low intake of rice; DP2 was characterized by a high intake of fish, chicken, processed meat, and noodles and a low intake of soy products; and DP3 was characterized by a lower intake of fruits and confectionaries. Higher DP1 scores were significantly associated with a lower prevalence of DIS (p-for-trend = 0.012). A higher DP2 score was significantly associated with a higher prevalence of insomnia (p-for-trend = 0.032). There was no significant association between DP3 and insomnia symptoms (p-for-trend >0.05). CONCLUSION: Our results highlighted that a dietary pattern with a high intake of vegetables, soy products, and fruits may contribute to reducing insomnia symptoms among independent older adults.