Analysing food groups and nutrient intake in adults who met and did not meet the daily recommended vegetable intake of 350 g: the 2016 National Health and Nutrition Survey in Japan.

This study aimed to compare the differences in the intake of food groups and nutrients between Japanese adults who consumed the recommended daily vegetable intake (350 g/day) and those who did not. Dietary information was obtained from one-day dietary records collected from the 2016 National Health and Nutrition Survey, which was conducted in 46 prefectures in Japan. The participants aged ≥20 years (n = 21,606; 53.8% women) were classified into the < and ≥350 g/day groups. Inter-group differences for 17 food groups and 27 nutrients were assessed as percentages of consumers (food groups only) and energy-adjusted intake (units/MJ/d or % of total energy intake). Overall, 29% of participants consumed ≥350 g/day of vegetables. The ≥350 g/day group had a higher percentage of consumers and energy-adjusted intakes for all vegetable subgroups than the <350 g/day group. For other food groups, the ≥350 g/day group had higher percentages of consumers for all food groups, except for cereals, eggs, and condiments and seasonings, which showed no significant differences. However, the ≥350 g/day group had a significantly higher energy-adjusted intake for potatoes and other tubers, mushrooms, meats, and condiments and seasonings but a significantly lower value for cereals, eggs, savoury snacks and confectionaries, and beverages. The ≥350 g/day group had a significantly higher intake of almost all (25/27) nutrients, including sodium, than the <350 g/day group. Participants with vegetable intake ≥350 g/day might have a more favourable intake of food groups and nutrients; however, watching for salt intake is necessary when promoting vegetable intake.

[Corrigendum: How accurate are self-reported anthropometrics among the Japanese? A scoping review].

　Nihon Koshu Eisei Zasshi(JAPANESE JOURNAL OF PUBLIC HEALTH), Vol. 70 (2023) No. 12 pp.817-827.

Mushroom intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study (CIRCS).

It is uncertain whether dietary intake of mushrooms rich in dietary fibre and several antioxidants is associated with a lower risk of dementia. We sought to examine prospectively the association between mushroom intake and the risk of disabling dementia. We performed a prospective study involving 3750 people aged 40 to 64 years residing in three communities who participated in an annual cardiovascular risk survey from 1985 to 1999. Cases of incident disabling dementia were surveyed from 1999 to 2020. We calculated the hazard ratios (HR) and 95 % CI for incident total dementia according to mushroom intake among participants with or without a history of stroke. During a mean 16·0 years' follow-up in 3739 eligible participants, 670 people developed disabling dementia. For women, mushroom intake was inversely associated with the risk of total dementia and the association was confined to dementia without a history of stroke. The multivariable HR (95 % CI) for total dementia in women were 0·81 (0·62, 1·06) for mushroom intake of 0·1-14·9 g/d and 0·56 (0·42, 0·75) for mushroom intake above 15·0 g/d (Pfor trend = 0·003) compared with no intake. The corresponding HR (95 % CI) for dementia without a history of stroke were 0·66 (0·47, 0·93) and 0·55 (0·38, 0·79) (Pfor trend = 0·01). In men, no associations were observed between mushroom intake and the risk of disabling dementia. Among Japanese women, dietary mushroom intake was associated with a lower risk of disabling dementia.

[How accurate are self-reported anthropometrics among the Japanese? A scoping review].

Objectives　Monitoring of obesity and underweight prevalence in general populations is crucial for the implementation of effective public health measures. Self-reported height and weight values are often used to assess the body mass index (BMI) in such epidemiological surveillance. However, it is known that using self-reported height and weight may underestimate the prevalence of obesity (BMI≥25 kg/m2), while its accuracy for underweight (BMI<18.5 kg/m2) prevalence is not well-understood. The aim of this study was to conduct a scoping review on the accuracy of self-reported anthropometrics in the Japanese population, where both obesity and underweight are prevalent.Methods　Using PubMed and CiNii Research, a literature search was conducted for studies published in English or Japanese by 2022 that were conducted in Japan and compared self-reported and measured height, weight, or/and BMI. The study design and mean reported errors (mean of reported values－mean of measured values) were extracted and tabulated, and differences by BMI categories were also considered.Results　A total of 17 studies, with 11 being published in English, were included in this review. These studies were conducted in nationwide cohort studies (n=4), local populations (n=4), workplaces (n=3), and educational institutions (n=6), with diverse age ranges (10-91 years) and sample sizes (<100 to >30,000). Although the degree of mean reporting error varied between studies, most of the studies reported that height was overreported, weight was underreported, and BMI was underestimated. In the three studies that reported mean reporting errors by BMI category, the direction of reporting error for height remained consistent across all body size categories, while weight and BMI were overreported and overestimated only among the underweight. Four studies in adults showed that 14.2-37.6% of actually obese individuals and 11.1-32.3% of underweight individuals were misclassified as 'normal range' (18.5≤BMI<25 kg/m2) based on self-reporting, while 0.8-5.4% and 1.2-4.1% of individuals actually within the normal range were misclassified as 'underweight' and 'obese' based on self-report, respectively.Conclusion　This study suggests that using BMI based on self-reported height and weight can underestimate the prevalence of both obesity and underweight in the Japanese population. These biases should be taken into consideration when using self-reported anthropometrics in epidemiological studies.

Dietary behaviours and related lifestyles according to the presence or absence of skipping breakfast in Japanese adults: the JPHC-NEXT study.

OBJECTIVE: To assess dietary behaviours and related lifestyles according to the presence or absence of skipping breakfast. DESIGN: We analysed the cross-sectional data from a baseline survey of a large-scale population-based cohort study in Japan conducted in 2011-2016. Participants provided information on dietary behaviours and lifestyles through a self-administered questionnaire. Skipping breakfast was defined as not eating breakfast at least once a week and was classified according to the frequency of skipping breakfast as 1-2, 3-4 or ≥5 times/week. SETTING: Sixteen municipalities in seven prefectural areas across Japan under the Japan Public Health Centre-based prospective study for the Next Generation. PARTICIPANTS: 112 785 residents (51 952 males and 60 833 females) aged 40-74 years. RESULTS: After adjustment for age, socio-demographic status, drinking status and smoking status, individuals who skipped breakfast at least once a week, compared with those who ate breakfast every day, were more likely to have adverse dietary behaviours such as frequent eating out (multivariable OR = 2·08, 95 % CI (1·96, 2·21) in males and 2·15, 95 % CI (1·99, 2·33) in females), frequent eating instant foods (1·89, 95 % CI (1·77, 2·01) in males and 1·72, 95 % CI (1·56, 1·89) in females). They had late bedtime (1·85, 95 % CI (1·75, 1·95) in males and 1·98, 95 % CI (1·86, 2·11) in females) and living alone (2·37, 95 % CI (2·17, 2·58) in males and 2·02, 95 % CI (1·83, 2·21) in females), using the logistic regression model. CONCLUSIONS: Both adult males and females who skipped breakfast were likely to eat out, to have a dietary habit of eating instant foods and have lifestyles such as late bedtime and living alone than those who ate breakfast.

Dietary intake of beans and risk of disabling dementia: The Circulatory Risk in Communities Study (CIRCS).

OBJECTIVE: To examine whether bean intake (including soybeans) among Japanese adults is associated with risk of disabling dementia severe enough to require care under the national insurance system. METHODS: This cohort study involved 3739 individuals aged 40 to 64 years. The participants were categorized into five groups based on their dietary bean intake estimated by a 24h dietary recall. Hazard ratios and 95% confidence intervals of disabling dementia were estimated using Cox proportional hazard models adjusted for potential confounding factors (smoking, drinking, and intakes of energy and fish). RESULTS: During the 59,681 person-year follow-up, 670 cases of disabling dementia were observed. A weak inverse association between bean intake and risk of disabling dementia was found; the multivariable hazard ratios (95% CIs) were 0.79 (0.62-1.00), 0.80 (0.63-1.01), 0.84 (0.67-1.06), and 0.78 (0.62-0.99) for the four groups with higher bean intake, respectively, compared with the lowest group (P for trend = 0.21). A significant inverse association was observed for dementia without a history of stroke; for the four groups with higher bean intake the multivariable hazard ratios were 0.81 (0.61-1.08), 0.70 (0.52-0.95), 0.71 (0.52-0.95), and 0.69 (0.51-0.92), respectively, (P for trend = 0.03). No such association was observed for dementia with history of stroke. The group with increased natto intake were inversely associated with risk of disabling dementia (P for trend = 0.003), but tofu intake was not (P for trend = 0.19). CONCLUSIONS: Bean intake was inversely associated with risk of disabling dementia in those without a history of stroke.

Dietary fiber intake and risk of incident disabling dementia: the Circulatory Risk in Communities Study.

OBJECTIVES: It has been hypothesized that dietary fiber intake has a beneficial impact on prevention of dementia, but the epidemiological evidence is scant. We sought to examine whether dietary fiber intake is inversely associated with risk of dementia requiring care under the national insurance (disabling dementia). METHODS: The study setting was the Circulatory Risk in Communities Study, involving 3739 Japanese individuals aged 40-64 years at the dietary surveys (1985-99). Dietary fiber intake was estimated using the 24-hour dietary recall method. Incident disabling dementia was followed up from 1999 through 2020. Disabling dementia was further classified into that with or without a history of stroke. Hazard ratios of disabling dementia according to quartiles of total, soluble, and insoluble fiber intake were calculated using the Cox proportional hazards model. RESULTS: During a median 19.7-year follow-up, a total of 670 cases of disabling dementia developed. Dietary fiber intake was inversely associated with risk of dementia: the multivariate hazards ratios (95% confidence intervals) were 0.83 (0.67-1.04), 0.81 (0.65-1.02), and 0.74 (0.57-0.96) for individuals with the second, third, and highest quartiles of dietary fiber intake, respectively, as compared with the lowest quartile (P for trend = 0.03). The inverse association was more evident for soluble fiber intake and was confined to dementia without a history of stroke. As for fiber-containing foods, potatoes, but not vegetables or fruits, showed a similar association. CONCLUSIONS: Dietary fiber intake, especially soluble fiber, was inversely associated with risk of disabling dementia in a general Japanese population.

Association between dietary intake of n-3 polyunsaturated fatty acids and risk of colorectal cancer in the Japanese population: The Japan Collaborative Cohort Study.

BACKGROUND: Epidemiological studies of the dietary intake of specific n-3 polyunsaturated fatty acids (PUFA) and anatomical subsite-specific colorectal cancer (CRC) are limited. We examined the prospective associations of total n-3 PUFA, marine-derived n-3 PUFA [combined eicosapentaenoic acid (EPA), docosapentaenoic acid (DPA), and docosahexaenoic acid (DHA)], and alpha-linolenic acid (ALA) as plant-derived n-3 PUFA with the risk of CRC by subsite in the Japan Collaborative Cohort Study. METHODS: The participants completed a self-administered food frequency questionnaire and had no prior history of CRC. Cox proportional hazards model was used to determine the associations between n-3 PUFAs intake and CRC risk overall and by anatomical subsite. RESULTS: During the median 13.8-year follow-up period, 699 of the 42,536 participants aged 40-79 years developed incident CRC. An inverse association was found between dietary ALA intake and the risk of distal colon cancer; the multivariable hazard ratios and 95% confidence intervals for the highest quartiles (Q4) were 0.41 (0.21-0.81; p trend = 0.01) compared with the lowest quartiles (Q1). Marine n-3 PUFA intake was not associated with CRC risk in the overall or anatomical subsite-specific analyses. CONCLUSION: Our findings suggest that higher ALA intake may be beneficial for lowering the risk of distal colon cancer.

Validity and reproducibility of the intake of trans-fatty acids estimated using a FFQ and characteristics of trans-fatty acid intake of the Japanese population: the JPHC FFQ Validation Study.

We aimed to validate a method for assessing trans-fatty acid (TFA) intake in the Japanese population using the FFQ developed in the 1990s from a prospective study that was based on the Japan Public Health Center-based Prospective Cohort Study. For FFQ validation, we included 565 participants (Cohort I: n 215, Cohort II: n 350) aged 40-69 years. We used a 28-d dietary record (DR) over 1 year and two FFQ administered before and after DR assessment. We calculated total TFA intake, TFA from industrial oils (i-TFA) and TFA from ruminants (r-TFA) considering a database of measurements obtained mainly from Japan. Spearman's rank correlation coefficients (CC) were computed for validity and reproducibility. Energy adjustments were applied using two methods considering the TFA measurement: density method for TFA % of total energy and residual method for TFA g/d. The total TFA intake (% of the total energy intake) was 0·08-0·76 % (median, 0·27-0·37 %) in DR of both cohorts and was 0·00-1·13 % (median, 0·30-0·40 %) in FFQ. The i-TFA accounted for approximately 50 % of the total TFA intake in DR and approximately 40 % in FFQ. For total TFA (% of the total energy intake), CC were 0·54-0·69, and weighted κ coefficients were 0·88-0·92 for both cohorts. The de-attenuated CC was 0·46-0·62 for i-TFA (g/d) and 0·57-0·68 for r-TFA (g/d). Our study showed that the validity and reproducibility of TFA intake estimation using the FFQ were reasonable, suggesting its suitability among the Japanese population with low-TFA intake.

Optimal Diet for Achieving Favorable Pregnancy Outcomes in East Asian Women-A Literature Review.

Ensuring nutritional adequacy during pregnancy is one of the necessary factors to achieve favorable pregnancy outcomes. In order to clarify the current optimal diet for achieving favorable pregnancy outcomes among East Asian women, we conducted a systemic literature review. English and Japanese articles were searched using PubMed and Igaku Chuo Zasshi. A total of 167 papers were retrieved, and six papers were finally selected for review. Five studies were conducted prospectively, and one was a case-control study. No significant associations were observed between dietary intakes and infant birthweight, but low intakes of fat and vitamin E were associated with preterm birth risk. Maternal diet with various food groups including vegetables was associated with higher birthweight and lower risk of preterm birth. A balanced diet with a combination of diverse food groups may be effective in achieving favorable pregnancy outcomes.

Low Periconceptional Dietary Intakes among Japanese Women: The Japan Environment and Children's Study (JECS).

Pregnancy is usually associated with dietary imbalances. We aim to assess the changes in Japanese women's diet and nutritional adequacy before and during pregnancy. In the Japan Environment and Children's Study (JECS), we recruited a large cohort of pregnant women (>100,000) from 15 Japanese communities. We assessed their diet before and during pregnancy by a food frequency questionnaire. The before and during pregnancy intakes of energy, macronutrients, and micronutrients were lower than the recommended level for Japanese women by 1% to 49%. The dietary intakes of pregnant women were lower than their intakes before pregnancy, except for milk, dairy products, and calcium. The daily during pregnancy intake of energy, carbohydrate, fat, protein, folic acid, and iron decreased by 85 kcal, 11.6 g, 2.3 g, 2.8 g, 20 µg, and 0.5 mg than the before pregnancy intake. Pregnant women's declined food and nutrients intakes were moderately correlated to their dietary intakes before pregnancy; the correlation coefficient ranged between 0.47 and 0.67. The inter-individual variability was greater than the intra-individual variability of the dietary intakes. Almost half of the pregnant women remained in the same intake quartile for all nutrients and food groups as before pregnancy. Yet, approximately 10% of pregnant women changed their pregnancy intake by ≥50% (≥2 quartiles up or down) compared to before pregnancy. In conclusion, the study identified low periconceptional dietary intakes among Japanese pregnant women. The low dietary intake of essential nutrients, such as folate, requires revising the Japanese national periconceptional dietary and supplementation guidelines.

Hydroxide Ion Mechanism for Long-Range Proton Pumping in the Third Proton Transfer of Bacteriorhodopsin.

In bacteriorhodopsin, representative light-driven proton pump, five proton transfers yield vectorial active proton translocation, resulting in a proton gradient in microbes. Third proton transfer occurs from Asp96 to the Schiff base on the photocycle, which is expected to be a long-range proton transfer via the Grotthuss mechanism through internal water molecules. Here, large-scale quantum molecular dynamics simulations are performed for the third proton transfer, where all the atoms (∼50000 atoms) are treated quantum-mechanically. The simulations demonstrate that two reaction paths exist along the water wire, namely, via hydronium and via hydroxide ions. The free energy analysis confirms that the path via hydroxide ions is considerably favorable and consistent with the observed lifetime of the transient water wire. Therefore, the proposed hydroxide ion mechanism, as in the first proton transfer, is responsible for the third long-range proton transfer.

Consumption of meals prepared away from home is associated with inadequacy of dietary fiber, vitamin C and mineral intake among Japanese adults: analysis from the 2015 National Health and Nutrition Survey.

BACKGROUND: Consumption of home-prepared meals may lead to better nutritional intake. Few studies have examined the association between the frequency of consuming meals prepared away from home and the inadequacy of nutritional intake based on nutritional standards and food group intake. We therefore aimed to investigate this issue among Japanese adults. METHODS: This study was a secondary analysis of the 2015 National Health and Nutrition Survey in Japan, involving 921 men and 1300 women aged 18-64 years, conducted as a cross-sectional survey. The frequency of consuming meals prepared away from home was defined using two questions inquiring about the frequency of eating out and take-away meals. Data on dietary intake were collected using a one-day semi-weighed household dietary record. Participants were stratified into three groups based on the frequency of consuming meals prepared away from home (High, Moderate, Low). The inadequacy of each nutrient intake was assessed by comparing estimated average requirement (EAR) level for 14 nutrients and the range of the dietary goal (DG) for seven nutrients according to the 2015 version of the Dietary Reference Intakes for Japanese. Group differences in nutrients adequacy were assessed using the covariate and logistic regression analysis. Food intake was also compared across the groups by classifying each food item into 17 groups based on Standard Tables of Food Composition. RESULTS: The proportion of participants who consumed home-prepared meals almost every day were 34.9% among men and 46.8% among women, and the proportion of those consuming a higher frequency of meals prepared away from home were 14.7 and 6.3%, respectively. A higher frequency of consuming meals prepared away from home was associated with inadequacy of dietary fiber, vitamin C and minerals (iron, magnesium and potassium) intake, and with lower intake of vegetables and higher intake of fat and oils. CONCLUSIONS: High frequency of consuming meals prepared away from home was associated with insufficient intake of dietary fiber, vitamin C and multiple minerals among Japanese adults. These nutrients may be the potential target of interventions aimed at improving nutrient intake in individuals who predominantly eat food prepared away from home.

Dietary sodium:potassium ratio and CVD risk factors among Japanese adults: a retrospective cross-sectional study of pooled data from the National Health and Nutrition Survey, 2003-2017.

Few studies have reported associations between the Na:K ratio and risk factors related to CVD among the general population in Asian countries. This study aimed to investigate the dietary Na:K ratio association with CVD risk factors among Japanese adults. This retrospective cross-sectional study included 48 800 Japanese participants (19 386 men and 29 414 women) aged ≥20 years, registered in the 2003-2017 National Health and Nutrition Survey. Multivariate OR and 95 % CI for risk of hypertension, high glycated HbA1c levels, hypercholesterolaemia, low serum levels of HDL-cholesterol and high non-HDL-cholesterol levels according to the Na:K ratio were estimated using logistic regression models. Dietary Na:K ratio decreased for both men and women from 2003 to 2017. Higher Na:K ratio and higher hypertension prevalence were observed (multivariate OR (fifth v. first quintiles) 1·27, 95 % CI 1·15, 1·40; Pfor trend < 0·001 for men and 1·12, 95 % CI 1·01, 1·23; Pfor trend = 0·007 for women). Higher Na:K ratio was associated with higher prevalence of high HbA1c levels in men (multivariate OR 1·56, 95 % CI 1·24, 1·96). Prevalence of low HDL-cholesterol levels was increased with higher Na:K ratio (Pfor trend =0·002 for men and <0·001 for women). No significant associations were found between Na:K ratio and hypercholesterolaemia in men or high non-HDL-cholesterol levels in both men and women. Our findings suggest that dietary Na:K ratio is associated with several CVD risk factors among Japanese adults.

Longitudinal Trends in Blood Pressure Associated With the Frequency of Laughter: The Circulatory Risk in Communities Study (CIRCS), a Longitudinal Study of the Japanese General Population.

BACKGROUND: The frequency of laughter has been associated with cardiovascular disease and related biomarkers, but no previous studies have examined association between laughter and changes in blood pressure levels. We sought to identify temporal relationships between frequency of laughter in daily life and systolic and diastolic blood pressure changes in participants from 2010 through 2014. METHODS: Participants were 554 men and 887 women aged 40-74 years who answered self-administered questionnaire quantifying frequency of laughter at baseline. We measured participant blood pressure levels twice using automated sphygmomanometers for each year from 2010 to 2014. The associations between laughter and changes in blood pressure over time were analyzed using linear mixed-effect models. RESULTS: There was no significant difference in blood pressure according to frequency of laughter at baseline in either sex. Men with frequency of laughter 1 to 3 per month or almost never had significantly increased systolic and diastolic blood pressure levels over the 4-year period (time-dependent difference: 0.96 mm Hg (95% confidence interval [CI], -0.2 to 1.8; P = 0.05). Changes in blood pressure associated with infrequent laughter (ie, 1 to 3 per month or almost never) were evident in men without antihypertensive medication use over 4 years (0.94 mm Hg; 95% CI, -0.2 to 2.0; P = 0.09) and men who were current drinkers at baseline (1.29 mm Hg; 95% CI, -0.1 to 2.3; P = 0.04). No significant difference was found between frequency of laughter and systolic (0.23 mm Hg; 95% CI, -1.0 to 1.5; P = 0.72) and diastolic (-0.07 mm Hg; 95% CI, -0.8 to 0.7; P = 0.86) blood pressure changes in women. CONCLUSIONS: Infrequent laughter was associated with long-term blood pressure increment among middle-aged men.

Association between free sugar intake and nutrient dilution among Japanese children and adolescents: the 2016 National Health and Nutrition Survey, Japan.

The influence of free sugar intake on nutrient intake remains unclear in Japanese children and adolescents with relatively low free sugar intake. This cross-sectional study aimed to investigate the relationship between free sugar and selected nutrient intakes using data from the 2016 National Health and Nutrition Survey, Japan, based on the WHO recommendations (<5 % or <10 % of energy (%E)) for free sugar intake. A 1-d weighed dietary record was assessed in Japanese children and adolescents (aged 1-19 years; n 2919). Mean intakes for selected nutrients and food groups were compared according to free sugar intake categories (<2·5 %E, 2·5 to <5 %E, 5 to <10 %E and ≥10 %E) with adjustment for sex, age and weight status. Inverse associations were observed between intakes of free sugars and twenty-one of twenty-four micronutrients assessed, except for vitamins A and C and Ca. Significantly reduced intakes were identified for twenty-two and fourteen micronutrients in the ≥10 %E and 5 to <0 %E categories, respectively, compared with the lower categories. Mean micronutrient intakes at the <2·5 %E category did not differ from those at the 2·5 to <5 %E category. Free sugar intake had positive associations with intakes of sugars and jams, confectioneries, fruit and vegetable juices, and soft drinks and negative associations with intakes of pulses and nuts and vegetables. This study showed that nutrient dilution was associated with higher free sugar intake among Japanese children and adolescents. The findings suggest that the WHO recommendations might help prevent nutrient dilution in Japanese children and adolescents.

Weight Change and Mortality from Cardiovascular Diseases: The Japan Collaborative Cohort Study.

AIM: The aim of this study was to assess the association between weight change and mortality due to cardiovascular diseases (CVDs) in a Japanese population. METHODS: We used the data of a population-based prospective cohort study that was conducted from 1988 to 1990 in 45 areas throughout Japan. Among a total of 69,681 men and women aged 40-79 with no history of CVD or cancer at baseline, the association between weight change from 20 years of age to baseline and CVD-related mortality was evaluated. RESULTS: During a median follow-up period of 19.1 years, we observed 4,274 deaths from total CVD. After adjusting for age, sex, and other potential confounding factors, compared with participants with a weight change of ＜2.5 kg (stable weight), participants with a greater weight change (either loss or gain) had an increased risk of mortality from total CVD (U-shaped association). The hazard ratios for the total CVD risk in participants with a weight loss and a weight gain of ≥ 12.5 kg were 1.50 (95% confidence interval [CI], 1.30-1.72) and 1.21 (95% CI, 1.07-1.36), respectively. The associations between weight change and risk of mortality from ischemic heart disease or stroke showed similar trends. The risk of intracerebral hemorrhage was associated with weight loss only. Weight change was not associated with mortality from subarachnoid hemorrhage. CONCLUSIONS: Weight loss or gain could be a risk factor for mortality from total or ischemic CVD, while weight loss could be a risk factor for intracerebral hemorrhage.

Association of Free Sugars Intake with Cardiometabolic Risk Factors among Japanese Adults: The 2016 National Health and Nutrition Survey, Japan.

The relationship between free sugars intake and cardiometabolic risk factors is unclear in Japanese adults. This cross-sectional study aimed to investigate this association using data from the 2016 National Health and Nutrition Survey, Japan. The percentage of energy intake from free sugars was estimated based on the 1-day weighed dietary record data of Japanese men (n = 4071) and women (n = 5794) aged ≥ 20 years. Associations between free sugars intake and cardiometabolic risk factors, including body mass index (BMI), waist circumference (WC), systolic and diastolic blood pressures, glycated haemoglobin (HbA1c) level and levels of serum total, low-density lipoprotein (LDL), and high-density lipoprotein (HDL) cholesterol, were investigated using linear regression and Dunnett's test, with the lowest category of quartiles as a reference. After adjustment for potential confounding factors, free sugars intake was inversely associated with blood pressures (men only) and HDL-cholesterol level (both sexes) and positively associated with total-cholesterol level (women only) and LDL-cholesterol level (both sexes), whereas no association was observed for BMI, WC, and HbA1c level. This study identified both positive and inverse associations of free sugars intake with cardiometabolic risk factors in Japanese adults.

Development of a screening method for determining sodium intake based on the Dietary Reference Intakes for Japanese, 2020: A cross-sectional analysis of the National Health and Nutrition Survey, Japan.

BACKGROUND: Although assessing nutrient intake through dietary surveys is desirable, it can be effort- and time-intensive. We aimed to develop a brief screening method for determining sodium intake in order to raise public awareness regarding the Dietary Reference Intakes for Japanese (DRI-J) 2020. METHODS: Using data from the 2015 National Health and Nutrition Survey, we compared dietary behaviours obtained from a self-administered questionnaire according to sodium intake, which was assessed from one-day dietary records by a semi-weighed method. Participants were divided into 4 groups based on the reference values of sodium (salt equivalent) shown in the DRI-J. We also randomly divided the participants into development and validation groups, and used logistic regression analysis to identify predictive factors for sex-specific DRI-J (<7.5 g/day in men and <6.5 g/day in women) and above-average intakes (≥10 g/day in men and women). RESULTS: Among the 6,172 Japanese individuals aged ≥20 years old, participants with lower sodium intake were found to use nutrition labels and had a lower frequency of eating out than those with higher intakes (P for difference < .001). Our final model for predicting sodium intake included adjusted sex, age, dietary behaviours, and consumption of mainly processed foods. In the development group, areas under the receiver operating characteristics curves were 0.747 and 0.741 for adherence to sex-specific DRI-J and above-average intake, respectively. The corresponding values in the validation group were 0.734 and 0.730, respectively. CONCLUSIONS: This method could easily identify sodium intake using dietary behaviours and specific food consumption, and is expected to be widely useful for health and nutrition education in Japan.

Trends in BMI among elderly Japanese population: findings from 1973 to 2016 Japan National Health and Nutrition Survey.

OBJECTIVE: To examine 44-year trends in height, weight and BMI, and the prevalence of overweight/obesity and underweight in the elderly Japanese population because Japan, the country with the longest life expectancy, has the highest ageing population. DESIGN: Using the nationally representative cumulative data from the Japan National Health and Nutrition Survey 1973-2016, sex-specific and age-adjusted mean height, weight and BMI, and the prevalence of overweight/obesity and underweight were calculated for each year. Trend analyses were performed using the Joinpoint Regression Program. Next, changes in height, weight and BMI, and the prevalence of overweight/obesity and underweight were estimated for each age group (65-69, 70-79 and >80 years) according to the birth year groups. SETTING: Japan. PARTICIPANTS: Individuals aged ≥65 years with complete data on height and body weight measurements (N 94 508). RESULTS: Trends in average height and weight increased over the four decades in both men and women. The prevalence of overweight/obesity dramatically increased and nearly tripled in men, accompanied with significantly decreased underweight prevalence. Furthermore, the increasing trend in average BMI and overweight/obesity prevalence in women reached a peak in 2002 and showed a decreasing trend thereafter, while a downward trend in underweight prevalence showed a gradual increase in women since 2003. CONCLUSIONS: Trends in height, weight and BMI among the elderly population should continue to be closely monitored in parallel with the effects of dietary changes, energy intake and physical activity (step counts).