Nutritional Adequacy Assessment of the Japanese Diet Using the Number of Dishes Compared to Existing Dietary Diversity Indices: A Cross-Sectional Analysis from the 2012 National Health and Nutrition Survey, Japan.

The Japanese diet has attracted attention as a factor contributing to the Japanese population's longevity. A typical Japanese meal, traditionally called "ichiju-sansai," is composed of various dishes. This study assessed the nutritional adequacy of the Japanese diet using the number of dishes in all meals (NDAM) compared to existing dietary diversity indices (DDIs). This cross-sectional study used data from the 2012 National Health and Nutrition Survey. A total of 25,976 participants aged ≥20 y were included in this study. NDAM was calculated for whole dishes or single foods (except supplements and beverages) from one-day weighted dietary records. The food variety score (FVS), number of foods, dietary diversity score (DDS), and number of food groups are some of the existing DDIs. NDAM had relatively high positive correlation coefficients with potassium, magnesium, and dietary fiber. The partial correlation coefficients with an indicator of the overall nutrient adequacy of NDAM was 0.42 for men and 0.42 for women. It was almost the same as that of the FVS (men: 0.44, women: 0.42) and DDS (men: 0.44, women: 0.43). On the other hand, NDAM, similar to existing DDIs, was also positively correlated with nutrient restriction in both sexes. These findings indicate that the nutrient adequacy of NDAM is similar to that of the existing DDIs. Because of the higher sodium intake and cholesterol intake in higher NDAM and existing DDIs, the effect of higher NDAM on health outcomes must be investigated in future studies.

Association of daily nutrient intake with breakfast and snack consumption among young Japanese adults aged 20-39 years: data from the 2012 National Health and Nutrition Survey.

Eating frequency has been associated with nutrient intake and diet quality. The aim of this study was to examine the association between daily nutrient and food group intake and consumption of breakfast and/or snacks among young Japanese adults, as secondary analysis of the 2012 National Health and Nutrition Survey in Japan involved 1420 men and 1659 women aged 20-39 years. Dietary intake data were collected using a one-day semi-weighed household dietary record. Participants were classified into four groups based their breakfast and snack consumption, defined as the consumption of any food or beverage that contained energy based on participant-defined eating occasions; both breakfast and snack consumption (B+S+), breakfast consumption without snacking (B+S-), breakfast skipping and snack consumption (B-S+) and breakfast skipping without snacking (B-S-). The proportion of breakfast skippers among men and women was 11·8 % and 6·6 %, whereas that of snack consumers among men and women was 55·3 % and 68·2 %, respectively. Energy, Mg potassium (in both sexes), vitamin B2, Ca, (only men) and folate and dietary fibre (only women) intakes were higher among breakfast and snack consumers than in the B+S- group. The nutrient intake level of the B+S- group was similar to that of the B-S+ group, whereas the B-S- group had lower energy (both sexes), Cu, dietary fibre and potassium (only women) intakes than the B+S- group. Snack consumption could supplement nutrients that may not be adequately consumed by three meals among young Japanese adults.

Comparison of Nutrient Reference Values for Food Labeling in Japan with CODEX Recommendations, Based on DRIs and Nutrient Intake in Japan.

To clarify the degree of consistency between the international recommendations and the national Japanese system, the nutrient reference values (NRVs) adopted by the CODEX were compared with current Japanese NRVs 2015, the dietary reference intakes for Japanese (DRIs-J) 2015, and actual nutrient intake levels by the Japanese population. The Japanese NRV for protein was high relative to CODEX NRV-R (i.e., NRV-Requirement). The Japanese NRVs for folate and calcium were low, and vitamin K was high, relative to each CODEX NRV-R. However, it was similar to the DRI-J values, and current intake levels for the Japanese population. For iron, calculation methods were different between the CODEX and Japan. Japanese iron NRV was calculated based on the RDA without menstruatating women, whereas CODEX NRV-R was calculated based on the INL98 of all adult men and women. Actual intake levels of iron for the Japanese population were similarly low. The Japanese NRV for sodium was high and potassium was low based on DRI-J values, relative to the CODEX NRV-NCD. For nutrients that show large discrepancies between the CODEX and Japanese NRVs, the values should be discussed further.

Personal behaviors including food consumption and mineral supplement use among Japanese adults: a secondary analysis from the National Health and Nutrition Survey, 2003-2010.

BACKGROUND AND OBJECTIVES: A daily mineral supplement is useful for those who are at risk of a deficiency. Some Western reports suggest that mineral supplement users have healthy behaviors and are not mineral-deficient. It is unknown whether the same phenomenon is observed in Japan where there is a different dietary culture. The aim of this study was to examine the characteristics of personal behaviors including food consumption nationwide among mineral supplement users from the National Health and Nutrition Survey in Japan 2003-2010. METHODS AND STUDY DESIGN: Data were obtained from 16,275 adults aged 20-59 years who completed sociodemographic, health status, and 1-day household dietary assessments. Supplement users were compared with non-users. Logistic regression models were utilized to identify the characteristics of food consumption and calcium and iron supplement use, using the medium intake group as a reference. RESULTS: Overall, 2.1% and 1.4% of adults reported using calcium supplements and iron supplements, respectively. Calcium supplement users were more likely to be physically active, non-smokers, and eat less fat compared with non-users. Furthermore, they were more likely than non-users to consume a higher intake of calcium from foods such as tea, vegetables, seaweeds, and fruits. Iron supplement users were more likely than non-users to be non-smokers. These individuals tended to have a high intake of seaweeds and fruits. CONCLUSIONS: Japanese adults who had healthier behaviors were more likely to use mineral supplements, especially calcium. Mineral supplement users tended to choose healthy foods such as seaweeds and fruits, without considering their overall mineral consumption.

[Current status of practice of providing dietary advice to pregnant women by members of the Japanese Midwives' Association. Knowledge and utilization of the "Dietary Guidelines for Pregnant and Lactating Women"].

OBJECTIVES: Midwives are actively involved in providing dietary advice to pregnant women. In order to describe the current status of prenatal dietary advice provided by midwives, we conducted a questionnaire survey inquiring about their knowledge and usage of the "Dietary Guidelines for Pregnant and Lactating Women" (Guidelines) issued by the Ministry of Health, Labour, and Welfare in 2006. METHODS: In total, 2000 members of the Japanese Midwives' Association were randomly selected for administration of the questionnaire. The recovery rate was 42.1%, and 785 responses were eligible for analyses. The questionnaire collected information on the respondent's age, years of work experience, current involvement in delivery practice, number of deliveries per year in the current affiliation, provision of dietary advice to pregnant women, and knowledge and usage of the Guidelines. RESULTS: The proportion of respondents in their 20 s was low (1.8%). About half of the respondents were practicing delivery. Further, 66.1% (519 midwives) reported they had knowledge of the Guidelines. Among those who had knowledge of the Guidelines and were currently providing dietary advice (426 midwives), 88.0% were using the Guidelines. The most frequently used item in the Guidelines was "Diet for preventing anemia" (75.8%). The least used item was "Shoku-iku (diet and nutrition education) for pregnant and lactating women" (58.5%). Midwives who were practicing delivery showed a significantly lower usage of the Guidelines than those who were not (84.9% vs. 92.6%, P = 0.02). Among midwives practicing delivery, the most common reason for not using the Guidelines was "using original educational material produced by oneself or the facility." CONCLUSION: Providing dietary advice to pregnant women constituted a large fraction of midwives' duties as well as delivery practice. About 90% of the midwives, who had knowledge of the Guidelines and provided dietary advice, were using the Guidelines. In order to increase the usage of individual items of the Guidelines, ready-to-use brochures should be developed for midwives.

Prevalence of inappropriate dietary supplement use among pregnant women in Japan.

We investigated the characteristics of dietary supplements and their use by 1,076 Japanese pregnant women, the majority of whom were in mid- to late pregnancy. The subjects completed a self-reported survey on their sociodemographic characteristics, supplement use, and attitudes towards diet. The overall prevalence of supplement use did not change before and after pregnancy (75%); however, daily use increased by approximately twofold with pregnancy (20.2% versus 37.2%). After the onset of pregnancy, supplements containing folic acid were taken for fetal health. Daily users were more likely to be older, have a greater awareness of the risk of neural tube defects (NTD), view supplement use as acceptable, have less diet anxiety, and have more advisers regarding diet. Respondents used supplements containing folic acid alone or with other ingredients. Folic acid intake is recommended to reduce the risk of NTD. However, supplement use began after pregnancy recognition, suggesting a lack of knowledge on the appropriate timing of folic acid use. Information about supplements was obtained mostly from newspapers, magazines, flyers, and stores. These results indicate that more accurate information regarding the optimal timing of folic acid intake and the safety of dietary supplements must be disseminated.

Distribution of vitamin E intake among Japanese dietary supplement and fortified food users: a secondary analysis from the National Health and Nutrition Survey, 2003-2009.

This study was performed to: (1) assess the prevalence of dietary supplement and fortified food use, (2) examine the differences in vitamin E intake with and without dietary supplementation and/or fortified food use, and (3) determine whether some individuals consume vitamin E above the tolerable upper intake level (UL). Data were obtained from 64,624 individuals (age, ≥1 y; 47.4% males) who completed a 1-d household dietary assessment that was part of the National Health and Nutrition Survey conducted in Japan, 2003-2009. The survey also obtained information on the brand or generic name of each dietary supplement or fortified food reported, including their ingredients, through dietary assessment. The prevalence of a potential risk of excess was estimated by the proportion of persons above the age-/sex-specific ULs provided by the Dietary Reference Intakes for Japanese 2010. Supplement use was reported by 5.8% of men and 7.7% of women, whereas fortified food consumption was reported by only 2.9% of men and 3.6% of women. Use of dietary supplements was most common among older women, whereas use of fortified foods was most common among younger women. Both dietary supplement and fortified food use accounted for maximum vitamin E intake; however, the use of dietary supplements and fortified foods had little effect on the median and 95th percentile intake values. None of the subjects consumed nutrients above the UL. The collected data confirm that the use of both dietary supplements and fortified foods contributes a small amount to nutrient intake in Japanese subjects.

Dietary intake of nutrients with adequate intake values in the dietary reference intakes for Japanese.

The Adequate Intake (AI) values in the Dietary Reference Intakes for Japanese (DRIs-J) 2010 were mainly determined based on the median intakes from 2 y of pooled data (2005-2006) from the National Health and Nutrition Survey-Japan (NHNS-J). However, it remains unclear whether 2 y of pooled data from the NHNS-J are appropriate for evaluating the intake of the population. To clarify the differences in nutrient intakes determined from 2 and 7 y of pooled data, we analyzed selected nutrient intake levels by sex and age groups using NHNS-J data. Intake data were obtained from 64,624 individuals (age: ≥1 y; 47.4% men) who completed a semi-weighed 1-d household dietary record that was part of the NHNS-J conducted annually in Japan from 2003 to 2009. There were no large differences between the median intakes calculated from 2 or 7 y of pooled data for n-6 or n-3 polyunsaturated fatty acids (PUFAs), vitamin D, pantothenic acid, potassium, or phosphorus. When the AI values and median intakes were compared, there was no large difference in the values for n-6 or n-3 PUFAs, pantothenic acid, or phosphorus. Conversely, the AI values for vitamin D and potassium differed from the median intakes of these nutrients for specific sex and age groups, because values were not based on NHNS-J data. Our results indicate that 2 y of pooled data from the NHNS-J adequately reflect the population's intake, and that the current system for determination of AI values will be applicable for future revisions.

Elevated maternal serum folate in the third trimester and reduced fetal growth: a longitudinal study.

This study aimed to examine the association of fetal growth and elevated third trimester maternal serum folate due to folic acid (FA) supplement intake. Dietary intake, use of FA supplements, weight, and blood biomarkers of B-vitamins (serum folate, pyridoxal, vitamin B(12), and plasma total homocysteine) were observed in 33 healthy pregnant women at the third trimester (average gestational age 35 wk). Birth outcomes were assessed through hospital birth records. Infant anthropometry and maternal blood biomarkers were followed up at 1 mo postpartum. Fourteen women were taking FA supplements at the third trimester. Dietary intake was similar among FA users and non-users, but serum folate and pyridoxal were significantly higher in users (11.6±6.7 vs. 6.1±3.2 ng/mL, and 13.8±21.7 vs. 3.2±1.4 ng/mL, respectively). Plasma total homocystein (tHcy) was higher in non-users compared to users, but not significantly. Nine FA users and eight non-users had low serum vitamin B(12) values (<203 pg/mL). Nine FA users and all non-users had low serum pyridoxal values (<7.0 ng/mL). Infant birthweight was significantly lower in users compared to non-users (2,894±318 vs. 3,154±230 g). At 1 mo postpartum, infant weight and length were similar between FA users and non-users, but infant weight gain was larger in users. Higher serum folate values due to FA use in the third trimester was related to reduced fetal size. Excess FA under low vitamin B(6) and B(12) status may affect fetal growth.