Development of a food-based diet quality score for Japanese: associations of the score with nutrient intakes in young, middle-aged and older Japanese women

Association Between Periconceptional Diet Quality and Hypertensive Disorders of Pregnancy: The Japan Environment and Children's Study

BACKGROUND

Little is known about the relationship of healthy diets, which are widely recommended to prevent diseases in general populations, with the risk of hypertensive disorders of pregnancy (HDP), particular among non-Western populations with different dietary habits. We aimed to investigate the association between periconceptional diet quality and the risk of HDP among pregnant Japanese women.

METHODS AND RESULTS

Dietary intake over 1 year before the first trimester of pregnancy was assessed using a validated, self-administered food frequency questionnaire among 81 113 pregnant Japanese women who participated in a prospective cohort of the Japan Environment and Children's Study. Overall diet quality was assessed by the Balanced Diet Score (BDS) based on adherence to the country-specific dietary guidelines and the Dietary Approaches to Stop Hypertension (DASH) score. Cases of HDP were identified by medical record transcription. The association between diet quality and HDP risk was examined using Bayesian logistic regression models with monotonic effects. We identified 2383 (2.9%) cases of HDP. A higher BDS was associated with a lower risk of HDP. When comparing the highest with the lowest quintile of the BDS, the adjusted odds ratio (aOR) of HDP was 0.83 (95% credible interval [CrI], 0.73-0.94). The DASH score and HDP risk were inversely associated in a monotonic dose-response manner (aOR per 1-quintile increase in the DASH score, 0.92 [95% CrI, 0.89-0.95]).

CONCLUSIONS

A high-quality diet, which is recommended for disease prevention in general populations, before conception may also reduce the risk of HDP among pregnant Japanese women.

Periconceptional maternal diet quality and offspring wheeze trajectories: Japan Environment and Children's Study

BACKGROUND

The role of prenatal diet on childhood wheezing and subsequent risk of asthma is inconclusive, which may be partly due to the heterogeneity in wheezing phenotypes. We aimed to identify wheeze trajectories in early childhood and to examine their associations with periconceptional maternal diet quality.

METHODS

Data from 70,530 mother-child pairs of liveborn singletons from the Japan Environment and Children's Study were analysed. Wheezing was reported by caregivers using a modified International Study of Asthma and Allergies in Childhood questionnaire yearly from 1 to 4 years of age, from which trajectories were derived using group-based trajectory modelling. Maternal diet in the year preceding the first trimester of pregnancy was assessed using a validated food frequency questionnaire; overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Bayesian inference of multinomial logistic regression models was performed to examine the association between maternal diet quality and wheeze trajectory in early childhood.

RESULTS

We identified four wheeze trajectories: 'never/infrequent' (69.1%; reference group), 'early-childhood onset' (6.2%), 'transient early' (16.5%) and 'persistent' (8.2%). After adjustment for confounders, a higher quartile of maternal balanced diet score was associated with a lower risk of belonging to the 'transient early' and 'persistent' wheeze trajectories compared with the 'never/infrequent' wheeze trajectory by 10% of both. Maternal balanced diet score was not associated with belonging to the 'early-childhood onset' wheeze trajectory.

CONCLUSION

Improving maternal diet quality prior to conception may reduce certain wheeze phenotypes in early childhood.

Development of the Scores for Traditional and Modified Japanese Diets

Increasing attention is being paid to the role of diet quality in the prevention and management of non-communicable diseases. We developed a scoring system for the traditional Japanese diet and its modified version considering the dietary culture in Japan, dietary guidelines for the Japanese, and updated evidence for disease prevention. The traditional Japanese diet comprises white rice, miso soup, soybean products, vegetables, mushrooms, seaweeds, fish and shellfish, high-sodium foods, and green tea. In the modified Japanese diet, unprocessed or minimally refined rice and raw vegetables, milk and dairy products, and fruits were additionally considered, while salty food was reverse-scored. The cutoff for the intake frequency of each food/food group was determined with reference to a health survey of >12,000 workers. Among the participants in the validation study, we confirmed the nutritional gradient with increasing scores in the expected direction. The scores were closely correlated with the respondents' backgrounds, including occupational factors. This simple scoring system can be used for diet quality assessments and epidemiological research.

Periconceptional diet quality and its relation to blood heavy metal concentrations among pregnant women: The Japan environment and Children's study

BACKGROUND

Diets contain toxic chemical contaminants as well as essential nutrients, both of which influence the intrauterine environment for foetal growth. However, whether a high-quality diet that is nutritionally healthy also results in lower exposure to chemical contaminants is unknown.

OBJECTIVE

We examined associations between periconceptional maternal diet quality and circulating concentrations of heavy metals during pregnancy.

DESIGN

Dietary intake over the year prior to the first trimester of pregnancy was assessed using a validated, self-administered food frequency questionnaire among 81,104 pregnant Japanese women who participated in the Japan Environment and Children's Study. Overall diet quality was determined using the Balanced Diet Score (BDS) based on the Japanese Food Guide Spinning Top, the Healthy Eating Index-2015 (HEI-2015), the Dietary Approaches to Stop Hypertension (DASH) score and the Mediterranean diet score (MDS). We measured whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) during the second or third trimester of pregnancy.

RESULTS

After controlling for confounders, all diet quality scores were positively associated with blood Hg concentrations. By contrast, higher BDS, HEI-2015 and DASH scores were associated with lower concentrations of Pb and Cd. Although the MDS was positively associated with concentrations of Pb and Cd, when dairy products were classified as a beneficial (rather than detrimental) food component, these associations were attenuated.

CONCLUSION

A high-quality diet may reduce exposure to Pb and Cd but not Hg. Further studies are required to determine the optimal balance between mercury exposure risk and nutritional benefits of high-quality diets prior to pregnancy.

Development of a Diet Quality Score for Japanese and Comparison With Existing Diet Quality Scores Regarding Inadequacy of Nutrient Intake

BACKGROUND

Few studies have explored optimal diet quality scores in Japan.

OBJECTIVES

We developed a Diet Quality Score for Japanese (DQSJ) and examined the associations of DQSJ and existing diet quality scores with inadequacy of nutrient intake in Japanese adults.

METHODS

Candidate components of the DQSJ were extracted from well-established diet quality scores: Healthy Eating Index-2015 (HEI-2015), Alternate Healthy Eating Index-2010 (AHEI-2010), Alternate Mediterranean Diet score (AMED), and Dietary Approaches to Stop Hypertension (DASH). From candidates, we selected the components of the DQSJ, considering potential health effects of the components (from the Global Burden of Disease Study) and dietary intake in Japan. The DQSJ included 10 components: fruits, vegetables, whole grain, dairy, nuts, legumes, fish, red and processed meat, sugar-sweetened beverages, and sodium. We calculated the DQSJ, HEI-2015, AHEI-2010, AMED, DASH, and Japanese Food Guide Spinning Top score (JFGST) based on 4-d dietary records of 392 Japanese aged 20-69 y. Inadequate intakes of 21 nutrients were assessed using the DRIs for Japanese. Logistic regression was used to examine the prevalence of inadequate nutrient intake according to quartiles of the scores.

RESULTS

All examined scores except the JFGST were moderately to strongly correlated with each other (Spearman correlation coefficients: 0.52-0.84). They were inversely associated with the prevalence of inadequate intake of most nutrients (n = 16 for DQSJ and HEI-2015, n = 13 for AHEI-2010 and DASH, n = 17 for AMED, compared with n = 4 for JFGST). AMED was also positively associated with the prevalence of inadequate sodium intake, whereas no such associations were observed for the other scores.

CONCLUSIONS

Similar to HEI-2015, AHEI-2010, and DASH, the DQSJ was generally associated with the low prevalence of inadequate intake of most nutrients in Japanese adults. Further evaluations against biomarkers and health outcomes are warranted.

Periconceptional maternal diet quality influences blood heavy metal concentrations and their effect on low birth weight: the Japan Environment and Children's Study

BACKGROUND

Both poor maternal nutrition and toxic heavy metal exposure influence foetal growth and development. However, whether consumption of a variety of healthy foods modifies the association between prenatal heavy metal exposure and foetal growth is unknown.

OBJECTIVE

We examined whether long-term maternal diet quality in periconception modifies the associations between maternal circulating concentrations of heavy metals and foetal growth.

DESIGN

Data of 72,317 Japanese women who delivered singleton infants was extracted from the Japan Environment and Children's Study. Maternal diet over a 1-year before the first trimester of pregnancy was assessed using a validated food frequency questionnaire, and overall diet quality was determined using the balanced diet score based on the Japanese Food Guide Spinning Top. Maternal whole-blood concentrations of mercury (Hg), lead (Pb) and cadmium (Cd) were measured during the second/third trimester of pregnancy. Bayesian inference of multiple linear regression analysis was performed to evaluate the relationships between maternal diet quality and the blood concentrations of heavy metals; Bayesian logistic regression was used to analyse the risk of low birth weight (LBW; <2,500 g).

RESULTS

After controlling for confounders, a high maternal balanced diet score was associated with low concentrations of blood Pb and Cd and high Hg. While all heavy metals assessed were positively associated with LBW risk, a higher maternal balanced diet score was negatively associated with LBW risk. A high-quality maternal diet attenuated the effect of Pb on LBW, an effect that was more marked at high blood Pb concentrations.

CONCLUSION

A high-quality, 'well-balanced' diet prior to conception may reduce exposure to some heavy metals and mitigate the elevated risk of LBW associated with prenatal Pb exposure in Japanese mother-child pairs.

Cross-Sectional Associations of Intakes of Starch and Sugars with Depressive Symptoms in Young and Middle-Aged Japanese Women: Three-Generation Study of Women on Diets and Health

The relationship between the intakes of saccharide subtypes and depressive symptoms is unclear in Asian countries. This cross-sectional study aimed to investigate this association among 3963 young (age of 18 years) and 3826 middle-aged (mean age of 47.8 years) Japanese women. The intakes of starch, total sugars, free sugars, sucrose, lactose, glucose, and total fructose were assessed using a validated diet history questionnaire. The prevalence of depressive symptoms was 22.0% and 16.8% among young and middle-aged women, assessed using the Center for Epidemiologic Studies Depression (CES-D) score. After adjusting for potential confounding factors, higher starch intake was associated with a lower prevalence of depressive symptoms in young women with an odds ratio (OR) of the fourth to the first quintiles of 0.75 (95% confidence interval (CI): 0.57, 0.99). Moreover, higher intakes of sugars (except for lactose) were associated with a higher prevalence of depressive symptoms in young women, with ORs (95% CI) of the fifth to the first quintiles ranging from 1.30 (0.995, 1.69) for glucose to 1.47 (1.12, 1.93) for sucrose. These associations were not observed in middle-aged women. Future prospective studies are needed to confirm these findings.

Adherence to the Japanese Food Guide: The Association between Three Scoring Systems and Cardiometabolic Risks in Japanese Adolescents

The Japanese Food Guide Spinning Top (JFGST) indicates optimal intake of five food groups (grain, fish and meat, vegetables, milk, and fruits) and sugar and confectionaries. We aimed to investigate whether adherence to the JFGST in 8th grade junior high school students (n = 3162) was associated with cardiometabolic risks and how different scorings of the JFGST influenced the associations. Metabolic risks were assessed from anthropometrics, blood pressure measurements, and blood glucose and lipid profile measurements. Three types of scoring adherent to the JFGST were analyzed (10 points were given for each item with optimal intake; range: 0–60): the original scoring (ORG scoring); first modified scoring, which had no upper limits for vegetables and fruits (MOD1 scoring); and MOD2 scoring without upper limits for five dishes (MOD2 scoring). The MOD2 scoring was positively associated with dietary fiber, potassium, calcium, and vitamins. All types of scorings were associated with low glucose levels (p ≤ 0.001); the MOD2 scoring was associated with low systolic blood pressure (p = 0.001) and low cardiometabolic risk (p = 0.003). Our findings suggest that Japanese adolescents adherent to the JFGST had low cardiometabolic risks and should not fall below lower limits for intake of the abovementioned five food groups.

A review of statistical methods for dietary pattern analysis

Background

Dietary pattern analysis is a promising approach to understanding the complex relationship between diet and health. While many statistical methods exist, the literature predominantly focuses on classical methods such as dietary quality scores, principal component analysis, factor analysis, clustering analysis, and reduced rank regression. There are some emerging methods that have rarely or never been reviewed or discussed adequately.

Methods

This paper presents a landscape review of the existing statistical methods used to derive dietary patterns, especially the finite mixture model, treelet transform, data mining, least absolute shrinkage and selection operator and compositional data analysis, in terms of their underlying concepts, advantages and disadvantages, and available software and packages for implementation.

Results

While all statistical methods for dietary pattern analysis have unique features and serve distinct purposes, emerging methods warrant more attention. However, future research is needed to evaluate these emerging methods’ performance in terms of reproducibility, validity, and ability to predict different outcomes.

Conclusion

Selection of the most appropriate method mainly depends on the research questions. As an evolving subject, there is always scope for deriving dietary patterns through new analytic methodologies.

Dietary Patterns and Muscle Mass, Muscle Strength, and Physical Performance in the Elderly: A 3-Year Cohort Study

OBJECTIVES

Nutritional support effectively prevents and treats sarcopenia; however, the influence of overall dietary patterns on sarcopenia parameters is less investigated. This study aimed to determine the association between adherence to Mediterranean-style diet (MD), Dietary Approaches to Stop Hypertension (DASH), Japanese Food Guide Spinning Top (JFG-ST), and modified JFG-ST (mJFG-ST) and muscle mass, muscle strength, and physical performance in community-dwelling Japanese elderly.

DESIGN AND SETTINGS

This prospective cohort study recruited individuals aged over 60 years from a community college in Nagoya, Japan.

PARTICIPANTS AND MEASUREMENTS

A total of 666 participants were followed up annually from 2014 to 2017. Demographic data, anthropometric measurements, and sarcopenia parameters including walking speed (WS), hand grip strength in the dominant hand (HGS), and skeletal mass index (SMI) were recorded. Self-recall dietary intake was assessed using a validated food frequency questionnaire comprising 29 food groups. Adherence to MD, DASH, JFG-ST, and mJFG-ST was determined by tertiles.

RESULTS

At baseline, the mean age of all participants (56.5% women) was 69.4±4.4 years. WS, HGS, and SMI were 1.4±0.2 (m/s), 28.9±8.1 (kg), and 6.7±1.0 (kg/m2), respectively. In longitudinal analysis, participants with higher JFG-ST adherence scores were more likely to have higher SMI (Q3 vs. Q1: mean difference, 0.048; p=0.04) after adjustment, and its benefits were more evident in men (Q2 vs. Q1: mean difference, 0.098; p=0.047; Q3 vs. Q1: mean difference, 0.091; p=0.017) than in women. WS and HGS were not associated with any type of dietary pattern.

CONCLUSIONS

Adherence to JFG-ST was positively associated with SMI in Japanese community-dwelling elderly adults aged over 60 years, specifically in men. The country-specific dietary recommendations are required to be developed for sarcopenia prevention.

Cultural and life style practices associated with low inflammatory physiology in Japanese adults

Japan is an exceptionally healthy East Asian country with extended longevity. In addition, the typical levels of several proinflammatory proteins, including both C-reactive protein (CRP) and interleukin-6 (IL-6), are often reported to be low when compared to American and European populations. This analysis determined if blood levels of CRP and IL-6 were associated with 4 cultural practices reflective of Japanese behavior and customs -- drinking tea, eating seafood, consuming vegetables, and partaking in relaxing baths regularly - among 382 adults living in Tokyo. Regression models controlled for demographic factors, adiposity (BMI), physical exercise, smoking, alcohol use, and chronic illness (e.g., diabetes). Consuming a Japanese diet was associated with significantly lower CRP and IL-6 levels. More frequent bathing was associated with lower IL-6, but not specifically predictive of low CRP. This study has confirmed prior evidence for low inflammatory activity in Japanese adults and its association with several behavioral practices common in Japan.

Diet quality indices and their associations with health-related outcomes in children and adolescents: an updated systematic review

BACKGROUND

To describe a-priori diet quality indices used in children and adolescents, appraise the validity and reliability of these indices, and synthesise evidence on the relationship between diet quality and physical and mental health, and growth-related outcomes.

METHODS

Five electronic databases were searched until January 2019. An a-priori diet quality index was included if it applied a scoring structure to rate child or adolescent (aged 0-18-years) dietary intakes relative to dietary or nutrient guidelines. Diagnostic accuracy studies and prospective cohort studies reporting health outcomes were appraised using the Academy of Nutrition and Dietetics Quality Criteria Checklist.

RESULTS

From 15,577 records screened, 128 unique paediatric diet quality indices were identified from 33 countries. Half of the indices' scores rated both food and nutrient intakes (n = 65 indices). Some indices were age specific: infant (< 24-months; n = 8 indices), child (2-12-years; n = 16), adolescent (13-18 years; n = 8), and child/adolescent (n = 14). Thirty-seven indices evaluated for validity and/or reliability. Eleven of the 15 indices which investigated associations with prospective health outcomes reported significant results, such as improved IQ, quality of life, blood pressure, body composition, and prevalence of metabolic syndrome.

CONCLUSIONS

Research utilising diet quality indices in paediatric populations is rapidly expanding internationally. However, few indices have been evaluated for validity, reliability, or association with health outcomes. Further research is needed to determine the validity, reliability, and association with health of frequently utilised diet quality indices to ensure data generated by an index is useful, applicable, and relevant.

REGISTRATION

PROSPERO number: CRD42018107630 .

Associations of Education With Overall Diet Quality Are Explained by Different Food Groups in Middle-aged and Old Japanese Women

Background

The disparity of overall diet quality by personal educational attainment has been a public issue. However, it remains unknown which food groups contribute to the disparity. This cross-sectional study assesses which food groups explain associations between education and overall diet quality in Japanese women.

Methods

A total of 3,788 middle-aged (mean age, 47.7 years) and 2,188 older women (mean age, 74.4 years), who lived in 47 prefectures in Japan, provided data on their education (low, middle, and high) and dietary intakes from a diet history questionnaire. A diet quality score (possible score 0–70) was calculated based on seven food components. Mean diet quality scores, with adjustment for lifestyle and neighborhood variables, were estimated by education using a general linear model, and Dunnett’s multiple comparison was conducted. Additionally, mean scores of each food component were estimated by education and compared using the same manner.

Results

After adjustment for lifestyle and neighborhood variables, mean diet quality score of high or middle education was higher than low education for both generations. Middle-aged women with high and middle education had higher scores of ‘milk’, ‘snacks, confection, and beverages’, ‘fruits’, and ‘vegetable dishes’ than those with low education. Older women with high and middle education had higher scores of ‘sodium from seasonings’ and ‘fruits’ than those with low education.

Conclusions

This study suggests that positive associations between education and diet quality are explained by different food groups in middle-aged and older Japanese women, which are independent of lifestyle and neighborhood variables.

Application of the Healthy Eating Index-2015 and the Nutrient-Rich Food Index 9.3 for assessing overall diet quality in the Japanese context: Different nutritional concerns from the US

Objectives

While it is widely perceived that the diet consumed by Japanese is healthy, empirical evidence supporting this notion is limited. In this cross-sectional study, we assessed the overall diet quality of Japanese using the Healthy Eating Index-2015 (HEI-2015) and Nutrient-Rich Food Index 9.3 (NRF9.3), and compared diet quality scores between Japanese and Americans.

Methods

We used 1-d dietary record data from 19,719 adults (aged ≥20 y) in the Japanese National Health and Nutrition Survey 2012 and the first 24-h dietary recall data from 4614 adults in the US NHANES 2011–2012.

Results

As expected, a higher total score of the HEI-2015 and NRF9.3 was associated with favorable patterns of overall diet in the Japanese population. The range of total score was wide enough for both HEI-2015 (5th percentile 37.2; 95th percentile 67.2) and NRF9.3 (5th percentile 257; 95th percentile 645). Both HEI-2015 and NRF9.3 distinguished known differences in diet quality between sex, age, and smoking status. The mean total scores of HEI-2015 and NRF9.3 were similar between Japanese (51.9 and 448, respectively) and US adults (52.8 and 435, respectively). However, component scores between the 2 populations were considerably different. For HEI-2015, Japanese had higher scores for whole fruits, total vegetables, green and beans, total protein foods, seafood and plant proteins, fatty acids, added sugars, and saturated fats, but lower scores for total fruits, whole grains, dairy, refined grains, and sodium. For NRF9.3, the intakes of vitamin C, vitamin D, potassium, added sugars, and saturated fats were more favorable in Japanese, while those of dietary fiber, vitamin A, calcium, iron, magnesium, and sodium were less favorable.

Conclusions

This study suggests the usefulness of HEI-2015 and NRF9.3 for assessing the diet quality of Japanese, as well as for highlighting different nutritional concerns between Japan and the US.

Status Besi dan Kualitas Diet pada Wanita Usia Subur Pranikah Obesitas di Kota Semarang

Background: Women of reproductive age are potentially to have double-burden malnutrition due to poor diet quality. Obesity-related anemia affects iron homeostasis (hypoferremia) through low-grade inflammation.Objectives: This study aimed to analyze the differences of iron status among women of reproductive age based on obesity status and diet quality based on iron and obesity status.Methods: A cross-sectional study of female students, aged 18-22 years old that classified as obese (n=25) and non-obese (n=25). Subjects were selected by proportional random sampling. This study used iron status and diet quality as variable datas. Blood samples were taken to determined iron status (Fe serum). Diet quality was analyzed by SQ-FFQ and DQI-I. Statistical analysis using Independent-T Test, One-way ANOVA, Kruskal Wallis, Mann Whitney tests.Results: There were 20% of obese subjects had low iron status and majority (94%) had low diet quality score (52.04±5.2). Iron status of obese women (83.9±20.7 µg/dl) significantly differed to non-obese women (99.2±26.1 µg/dl), p=0.027. Obese group with low iron status had lower diet quality and moderation component score, however adequacy score was higher than other groups, p<0.05. There were no significant differences in variation and overall balance among all groups, p>0.05.Conclusions: Iron status of obese women was significantly different than non-obese women. Obese group with low iron status had lower diet quality and moderation component score, however adequacy score was higher than other groupsABSTRAKLatar Belakang: Wanita Usia Subur (WUS) rentan terkena masalah gizi ganda akibat kualitas diet yang buruk. Obesitas terkait anemia disebabkan inflamasi tingkat rendah yang mempengaruhi homeostasis zat besi (hipoferrimia). Tujuan: Penelitian ini bertujuan untuk menganalisis perbedaan status besi WUS berdasarkan status obesitas, dan perbedaan kualitas diet berdasarkan status besi dan obesitas. Metode: Penelitian ini menggunakan desain cross-sectional, dengan subjek mahasiswi berjumlah 25 orang obesitas dan 25 orang non-obesitas, dipilih menggunakan teknik proportional random sampling. Data yang diambil berupa status besi (kadar Fe serum) melalui pengambilan sampel darah, dan kualitas diet menggunakan wawancara SQ-FFQ dan analisis DQI-I. Analisis menggunakan uji Independent-T Test, One-way ANOVA, Kruskal Wallis, dan Mann Whitney.Hasil: Sebanyak 20% WUS obesitas memiliki status besi rendah dan mayoritas subjek (94%) memiliki kualitas diet rendah (52,04±5,2). Status besi WUS obesitas (83,9±20,7µg/dl) berbeda signifikan dibandingkan WUS non-obesitas (99,2±26,1µg/dl), p=0,027. Kelompok WUS obesitas dengan status besi rendah memiliki skor kualitas diet dan komponen moderasi lebih rendah, namun memiliki skor kecukupan lebih tinggi dibandingkan kelompok lainnya, p<0,05. Komponen variasi dan keseimbangan keseluruhan pada semua kelompok tidak menunjukkan perbedaan signifikan, p>0,05.Kesimpulan: Status besi WUS obesitas signifikan lebih rendah dibandingkan WUS non-obesitas. Kelompok WUS obesitas dengan status besi rendah memiliki skor kualitas diet dan moderasi lebih rendah, namun memiliki skor kecukupan lebih tinggi dibandingkan kelompok lainnya. 

Reproducibility and Relative Validity of the Healthy Eating Index-2015 and Nutrient-Rich Food Index 9.3 Estimated by Comprehensive and Brief Diet History Questionnaires in Japanese Adults

We examined the reproducibility and relative validity of two measures of overall diet quality, the Healthy Eating Index-2015 (HEI-2015) and Nutrient-Rich Food Index 9.3 (NRF9.3), as estimated by well-established self-administered dietary assessment questionnaires for the Japanese, namely the comprehensive diet history questionnaire (DHQ) and the brief diet history questionnaire (BDHQ). Diet was assessed separately by two DHQs and two BDHQs at a 1-year interval and by 16-day weighed dietary records (DRs) in 121 women and 121 men aged 31–81 years. HEI-2015 and NRF9.3 were calculated from each method. The reproducibility correlation for the two questionnaires (intraclass correlation) ranged from 0.53 (HEI-2015 from BDHQ in men) to 0.77 (NRF9.3 from BDHQ in women). The validity correlation between the first questionnaires and DR (Pearson correlation) ranged from 0.37 (NRF9.3 from BDHQ in men) to 0.61 (NRF9.3 from DHQ and BDHQ in women). Bland–Altman plots showed poor agreement between the DHQ or BDHQ and DR, as well as the presence of weak proportional bias. Overall, these data indicate reasonable reproducibility and ranking ability of the DHQ and BDHQ for assessing the HEI-2015 and NRF9.3 and support their usefulness in future epidemiological research on the overall effects of Japanese diets on various health outcomes.

Diet quality indices for research in low- and middle-income countries: a systematic review

CONTEXT

Dietary intake research has increasingly focused on improving diet quality in low- and middle-income countries (LMICs). Accompanying this is the need for sound metrics to assess diet quality.

OBJECTIVE

This systematic literature review aims to describe existing diet quality indices for general populations and highlights recommendations for developing such indices for food system research in LMICs.

DATA SOURCES

Three electronic databases were searched for papers published between January 2008 and December 2017.

DATA EXTRACTION

Articles published in English and describing the development of an index to measure overall diet quality, irrespective of whether they were for high-income countries or LMICs, were included.

DATA ANALYSIS

Eighty-one indices were identified, over two thirds were based on national dietary guidelines from high-income countries. Of the 3 key diet quality dimensions, "diversity" was included in all 18 indices developed for LMICs, "moderation" was captured by most, and "nutrient adequacy" was included 4 times.

CONCLUSIONS

Indices need to be developed that include all dimensions, include foods and/or food groups rather than nutrients, use an optimal range for individual components in the score, and express the intake of healthy and unhealthy components separately. Importantly, validation of the index should be part of its development.

Diet quality scores in relation to metabolic risk factors in Japanese adults: a cross-sectional analysis from the 2012 National Health and Nutrition Survey, Japan

OBJECTIVE

Associations between the overall quality of Japanese diets and metabolic risk factors are largely unknown. This cross-sectional study investigated this issue using data from the 2012 National Health and Nutrition Survey, Japan.

METHODS

Dietary intake was assessed by a 1-day weighed dietary record in 15,618 Japanese adults aged ≥ 20 years. Overall diet quality was assessed by adherence to the Japanese Food Guide Spinning Top (JFG score), its modified version (modified JFG score), the Mediterranean diet score (MDS) and the Dietary Approaches to Stop Hypertension (DASH) score. Metabolic risk factors included BMI, waist circumference, blood pressure, total, HDL- and LDL-cholesterol and glycated haemoglobin.

RESULTS

While DASH score was consistently associated with favourable nutrient intake patterns (including higher micronutrient and dietary fibre intakes and lower SFA and sodium intakes), other scores were associated with both favourable and unfavourable aspects (e.g., lower micronutrient intakes for JFG score, higher SFA intakes for modified JFG score and higher sodium intakes for MDS). The associations with metabolic risk factors were also inconsistent and unexpected, including positive associations of JFG and modified JFG scores with LDL-cholesterol, inverse associations of MDS with HDL-cholesterol and null associations of DASH score with blood pressure.

CONCLUSIONS

This study did not show expected and consistent associations of the four available diet quality scores with nutrient intakes and metabolic risk factors in Japanese adults. This in turn suggests the need for a scientific base on which to develop an appropriate tool for assessing the quality of diets in the Japanese context.

Association between Adherence to the Japanese Food Guide Spinning Top and Sleep Quality in College Students

This study aimed to elucidate the association between adherence to the Japanese Food Guide Spinning Top (Food Guide score) and sleep quality in Japanese college students. We conducted a cross-sectional study of 175 Japanese college students aged 19–22 years in the eastern part of Gunma Prefecture to examine the association between the Food Guide score and sleep quality. A self-administered diet history questionnaire and the Pittsburgh Sleep Quality Index were used to assess habitual dietary intake and sleep quality, respectively. In the fully adjusted model, the odds ratios for poor sleep quality in the middle and highest tertile categories of the Food Guide score were 0.50 (95% confidence interval, 0.18–1.37) and 0.30 (95% confidence interval, 0.11–0.84), respectively, compared with those in the lowest tertile category (p for trend = 0.033). A well-balanced diet may be associated with good sleep quality in Japanese college students.

The Role of the Japanese Traditional Diet in Healthy and Sustainable Dietary Patterns around the World

As incomes steadily increase globally, traditional diets have been displaced by diets that are usually animal-based with a high content of “empty calories” or refined sugars, refined fats, and alcohol. Dietary transition coupled with the expansion of urbanization and lower physical activity have been linked to the global growth in the prevalence of obesity, overweight and life style-related non-communicable diseases. The challenge is in how to reverse the trend of high consumption of less healthy food by more healthful and more environmentally sustainable diets. The increasing recognition that each individual has specific needs depending on age, metabolic condition, and genetic profile adds complexity to general nutritional considerations. If we were to promote the consumption of low-energy and low salt but nutritious diets, taste becomes a relevant food quality. The Japanese traditional diet (Washoku), which is characterized by high consumption of fish and soybean products and low consumption of animal fat and meat, relies on the effective use of umami taste to enhance palatability. There may be a link between Washoku and the longevity of the people in Japan. Thus Washoku and umami may be valuable tools to support healthy eating.

Food-based diet quality score in relation to depressive symptoms in young and middle-aged Japanese women

Only a few studies have focused on the association between overall diet, rather than intakes of individual nutrients or foods, and depressive symptoms in Japanese. This cross-sectional study examined associations between a diet quality score and depressive symptoms in 3963 young (age 18 years) and 3833 middle-aged (mean age 47·9 (sd 4·2) years) Japanese women. Dietary information was collected using a diet history questionnaire. A previously developed diet quality score was computed mainly based on the Japanese Food Guide Spinning Top. The prevalence of depressive symptoms was 22·0 % for young women and 16·8 % for middle-aged women, assessed as a Center for Epidemiologic Studies Depression (CES-D) score ≥23 and ≥19, respectively. As expected, the diet quality score was associated positively with intakes of ‘grain dishes’, ‘vegetable dishes’, ‘fish and meat dishes’, ‘milk’ and ‘fruits’ and inversely with intakes of energy from ‘snacks, confection and beverages’ and Na from seasonings. After adjustment for potential confounders, OR for depressive symptoms in the highest v. lowest quintiles of the diet quality score was 0·65 (95 % CI 0·50, 0·84) in young women (Pfor trend=0·0005). In middle-aged women, the corresponding value was 0·59 (95 % CI 0·45, 0·78) (Pfor trend<0·0001). Analyses where the diet quality and CES-D scores were treated as continuous variables also showed inverse associations. In conclusion, this cross-sectional study showed that a higher diet quality score was associated with a lower prevalence of depressive symptoms in young and middle-aged Japanese women. Prospective studies are needed to confirm a public health relevance of this finding.