Abstract Background The high prevalence of low bone mass in young women in Japan has emerged as a serious health issue in recent years. Therefore, the aim of the present study was to reevaluate the relationship between genetic and dietary factors, as well as its influence on bone mass in young Japanese women, with particular emphasis on vitamin D receptor (VDR) gene polymorphisms and calcium intake. Methods A total of 499 Japanese women aged 20–24 years were enrolled in the study. The bone mass of the calcaneus was assessed using the quantitative ultrasound method and expressed as the osteo sono-assessment index (OSI). VDR gene polymorphisms ( Bsm I, Taq I, Apa I, and Fok I) were analyzed using DNA extracted from saliva. Calcium intake was assessed using the Food Frequency Questionnaire based on food groups (FFQg) and adjusted with the energy intake. Participants were divided into two groups based on the median calcium intake (250 mg/1000 kcal). Results Consequently, bone mass was significantly different among the Bsm I and Taq I genotypes after adjusting for body mass index (BMI) ( p = 0.030 and 0.019, respectively). In addition, the Bsm I AA and Apa I GT genotypes showed significant differences in bone mass between the calcium-intake groups, with low OSI in the low-calcium intake group and high OSI in the high-calcium intake group, respectively, even after adjusting for BMI ( p = 0.020 and 0.038, respectively). Conclusions These findings may prove instrumental in developing a logical approach towards preventing bone loss in young Japanese women.
Background Seasonal variations could systematically bias dietary intakes. This systematic review aimed to determine seasonal variations in dietary intake among Japanese adults.
Abstract 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.
Purpose This study aims to evaluate health- and diet-related information quality on Japanese Web pages and its correlation with search rankings. Design/methodology/approach Google searches were performed in August 2022 using seven popular search terms combining diet and health conditions. The Quality Evaluation Scoring Tool (QUEST), comprising seven items (authorship, attribution, type of study, conflict of interest, currency, complementary and tone), with a score ranging 0–28, was used to assess information quality. Descriptive statistics were used to analyze the median total QUEST score and the distribution of Web page quality. Spearman’s correlation coefficient was used to assess the correlation between the total QUEST score and search result ranking. Findings Of the 350 Web pages identified, 263 were selected for evaluation. The median total QUEST score was 12.5 (range 2.5–23.5), with 43% of Web pages classified as low quality (score = 11). Total QUEST scores varied by health condition, with “diabetes” related Web pages scoring highest and “cold” related ones scoring lowest. Only 23% of Web pages cited identifiable scientific studies. Search result ranking showed no significant correlation with the total QUEST score ( r = 0.06, P = 0.36). Originality/value This study suggested that Japanese Web pages require higher quality diet and health information, particularly regarding source attribution.
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
Background Both obesity and underweight are matters of global concern. Weight-related content frequently shared on social media can reflect public recognition and affect users’ behaviors and perceptions. Although X (Twitter) is a popular social media platform, few studies have revealed the content of weight-related posts or details of dietary behaviors for weight loss shared on X. Objective This study aims to describe body weight–related content frequently reposted on X, with a particular focus on dietary behaviors for weight loss, in English and Japanese. Methods We collected English and Japanese X posts related to human body weight having over 100 reposts in July 2023 using an application programming interface tool. Two independent researchers categorized the contents of the posts into 7 main categories and then summarized recommended weight loss strategies. Results We analyzed 815 English and 1213 Japanese posts. The most popular main category of the content was “how to change weight” in both languages. The Japanese posts were more likely to mention “how to change weight” (n=571, 47.1%) and “recipes to change weight” (n=114, 9.4%) than the English posts (n=195, 23.9% and n=10, 1.2%, respectively), whereas the English posts were more likely to mention “will or experience to change weight” (n=167, 20.5%), “attitudes toward weight status” (n=78, 9.6%), and “public health situation” (n=44, 5.4%) than Japanese posts. Among 146 English and 541 Japanese posts about weight loss strategies, the predominant strategies were diet (n=76, 52.1% in English and n=170, 31.4% in Japanese) and physical activities (n=56, 38.4% and n=295, 54.5%, respectively). The proportion of posts mentioning both diet and physical activity was smaller in Japanese (n=62, 11.5%) than in English (n=31, 21.2%). Among 76 English and 170 Japanese posts about dietary behaviors for weight loss, more than 60% of posts recommended increasing intakes of specific nutrients or food groups in both languages. The most popular dietary component recommended to increase was vegetables in both English (n=31, 40.8%) and Japanese (n=48, 28.2%), followed by protein and fruits in English and grains or potatoes and legumes in Japanese. Japanese posts were less likely to mention reducing energy intake; meal timing or eating frequency; or reducing intakes of specific nutrients or food groups than the English posts. The most popular dietary component recommended to decrease was alcohol in English and confectioneries in Japanese. Conclusions This study characterized user interest in weight management and suggested the potential of X as an information source for weight management. Although weight loss strategies related to diet and physical activity were popular in both English and Japanese, some differences in the details of the strategies were present, indicating that X users are exposed to different information in English and Japanese.
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.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.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.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%).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.