Association between the frequency of meals combining "Shushoku, Shusai, and Hukusai" (Staple food, main dish, and side dish) and intake of nutrients and food groups among Japanese young adults aged 18-24 years: a cross-sectional study

Spending Longer Time in the Kitchen Was Associated With Healthier Diet Among Japanese Older Women With Frailty

OBJECTIVE

To evaluate the conditional effect of time spent in the kitchen on the association between frailty status and healthy diet among older women.

DESIGN

Secondary analysis of an online cross-sectional survey conducted in January 2023.

PARTICIPANTS

Six hundred Japanese women (aged ≥ 65 years).

MAIN OUTCOME MEASURE(S)

Frailty status evaluated using the Kihon Checklist (25 affirmative questions assessing daily functions, weight status, and mental condition); healthy diet assessed by the days of consuming ≥ 2 meals that include staple, main and side dishes in a meal (SMS meal) in a day; and time spent in the kitchen.

ANALYSIS

Moderation analysis was used to evaluate the conditional effect of time spent in the kitchen on frailty status and SMS meal intake. Chi-square tests for independence were used to evaluate the differences in the Kihon Checklist items by frailty status.

RESULTS

Spending longer time in the kitchen indicated more frequent SMS meal intake and the trend was stronger among older women with frailty than those with robustness. All items except for 1 item regarding weight status (P = 0.15) were significantly associated with frailty status (P < 0.001).

CONCLUSIONS AND IMPLICATIONS

Further studies are needed to evaluate the causal relationship between frailty status, healthy diet, and kitchen use.

Relationship between Frequency of Meals Comprising Staple Grain, Main, and Side Dishes and Nutritional Adequacy in Japanese Adults: A Cross-Sectional Study

Meals comprising a staple grain, a main, and side dishes (SMS meals) promote good dietary intake, yet limited studies have examined their multifactorial relationship with dietary intake. We investigated how demographic characteristics, lifestyle, and dietary habits affect the relationship between SMS meal frequency and nutrient intake adequacy. This cross-sectional study analyzed survey data from 331 Japanese adults (208 men and 123 women) aged 30-69 years in February 2019. SMS meal frequency was evaluated according to respondents' answers to how many days a week they consumed ≥2 daily SMS meals. Dietary intake was evaluated using the brief self-administered diet history questionnaire. Differences in nutrient intake adequacy among groups according to SMS meal frequency were determined using multiple logistic regression. Less frequent SMS meals correlated with a lower intake of protein, water-soluble vitamins, and certain minerals, with more individuals falling below the estimated average requirement for nutrient intake. However, no relationship was found between SMS meal frequency and nutrient intake concerning tentative dietary goals for preventing lifestyle-related diseases. Our findings indicate that adopting SMS meals could achieve adequate intake of some nutrients and enhance overall diet quality among Japanese adults.

Association between the experience of exertional heat illness (EHI) and living conditions of collegiate student athletes

Exertional heatstroke (EHS), a severe form of exertional heat illness (EHI), is the third leading cause of death in athletes; thus, early detection and prevention of EHI can help prevent EHS, which is a life-threatening condition. This study aimed to clarify the association between the cognizance of experiencing EHI and living conditions and specific EHI symptoms among collegiate athletes. This study was conducted in October 2022 by administering a questionnaire to 237 male collegiate athletes. Of the 215 (90.7%) respondents, 197 (91.6%) provided valid responses; among them, 88 (44.7%) responded they had experienced EHI, while 109 (55.3%) had not. A history of medical examinations due to EHI, having experienced headaches during summer activities, and having read the EHI manual were factors indicating cognizance of EHI. The number of times meals containing a staple food, main dish, and side dish were eaten in a day was a factor in preventing EHI. Early detection of EHI is important for its prevention, and it is important that athletes themselves have knowledge of symptoms and can correctly self-diagnose EHI. Emphasizing the potential of a well-balanced dietary intake has the potential to prevent EHI is crucial.

Guardians' food literacy and breakfast skipping among Japanese school children

Children and adolescents who regularly skip breakfast are at a greater risk of obesity than those who regularly eat breakfast. Guardian's food literacy, defined in this study as a collection of a guardian's knowledge, skill, and attitude towards healthy food practices, may directly influence their child's dietary habits. Thus, this study utilized a food literacy scale to assess the relationship between guardians' food literacy and breakfast skipping among school-attending Japanese children and adolescents and the most commonly reported reasons for skipping breakfast. This was a cross-sectional study using survey data collected from a nationally representative sample of households in Japan (n = 1520). Our results show that 13.0% of children self-reported skipping breakfast at least once a week. Children in households where guardians reported higher knowledge and attitude scores had significantly lower odds of skipping breakfast (odds ratios = 0.90 [95% confidence interval: 0.83-0.98] and 0.81 [0.74-0.90], respectively). These findings suggest that a guardian's attitude and knowledge towards healthy food practices influence the frequency at which their child eats breakfast. Moreover, lower parental attitude scores were associated with children skipping due to not having enough time for breakfast in the morning. Improving guardians' food literacy may provide an avenue by which to decrease the rate of breakfast skipping among children and adolescents, thereby decreasing the risk of obesity and other adverse health outcomes.

Influence of education and subjective financial status on dietary habits among young, middle-aged, and older adults in Japan: a cross-sectional study

BACKGROUND

Research has suggested an association between lower socioeconomic status (SES) and unhealthy dietary habits. However, differences in the effects of different SES indicators and age remain unclear. The current study addressed this research gap by investigating the relationship between SES and unhealthy dietary habits, specifically focusing on educational attainment and subjective financial status (SFS) among varied age groups.

METHODS

Data were derived from a mail survey of 8,464 people living in a suburb of Tokyo, Japan. Participants were classified into three age groups (20-39 years: young adults; 40-64 years: middle-aged adults; and 65-97 years: older adults). SES was assessed based on individual educational attainment and SFS. Unhealthy dietary habits were defined as skipping breakfast and a low frequency of balanced meal consumption. Participants were asked how often they ate breakfast, and those who did not respond "every day" were categorized as "breakfast skippers." Low frequency of balanced meal consumption was defined as eating a meal that included a staple meal, main dish, and side dishes at least twice a day for less than five days per week. Poisson regression analyses with robust variance adjusted for potential covariates were used to determine the interactive effects of educational attainment and SFS on unhealthy dietary habits.

RESULTS

Individuals with lower educational attainment across all age groups skipped breakfast more frequently compared to those with higher educational attainment. For older adults, poor SFS was associated with skipping breakfast. Young adults with poor SFS and middle-aged adults with lower educational attainment tended to eat less balanced meals. In addition, an interaction effect was found in older adults, where those with lower education despite good SFS and those with poor SFS despite higher education were at a greater risk of falling into unhealthy diet.

CONCLUSIONS

The findings suggested that different SES indicators affect healthy dietary habits in different generations, and therefore, health policies should consider the potential influence of different SES on promoting healthier dietary habits.

Nutritional intake and metabolic parameters of Japanese university students with and without obesity: Sex-specific differences

OBJECTIVE

To establish effective methods of obesity prevention among young adults, we analyzed the relationship between obesity-related food intake and metabolic factors in Japanese university students.

METHODS

We performed a cross-sectional analysis of nutrient intake information and metabolic parameters among 1,206 Gifu University students categorized by body mass index.

RESULTS

The overweight/obesity rate was significantly higher in males. Additionally, among males, the intake of protein, potassium, magnesium, phosphorus, iron, zinc, all lipids/fats, and all metabolic parameters including blood sugar, hemoglobin A1c, uric acid, alanine aminotransferase, aspartate aminotransferase, low-density lipoprotein, high-density lipoprotein, triglycerides, and blood pressure significantly differed between the obese and non-obese groups. However, the same comparison among females revealed no significant differences in nutrient intake and significant differences in only half of the parameters. Among males, energy intake from protein and fat was significantly higher in the obese group, while the percentage of total energy intake from carbohydrates and fat was lower and higher, respectively, among females in the obese group.

CONCLUSIONS

Overeating of protein and fat in males and unbalanced nutrition in females are sex-specific characteristics of Japanese university students with obesity, and metabolic abnormalities in students with obesity are more remarkable in males than in females.

Japanese school children's intake of selected food groups and meal quality due to differences in guardian's literacy of meal preparation for children during the COVID-19 pandemic

In 2020, a state of emergency (SOE) was enforced by the Japanese government, which included temporary school closures with the aim of overcoming COVID-19 spread, which prevented access to school lunches. We evaluated the relationship between meal quality and guardians' literacy of meal preparation for a nationally representative sample of 1107 Japanese schoolchildren (aged 10-14 years) before, during, and after the SOE on the basis of 7 questions scored using a 5-point Likert scale. The guardians' literacy of meal preparation for children was divided into quartiles, with Q1 and Q4 including participants with the lowest and highest scores on food literacy, respectively. School lunch menu was handed out monthly to each household by their classroom teacher. The consumption of (i) meat, fish, or eggs and (ii) vegetables at least twice a day indicated "well-balanced dietary intake", which was less frequent in all four quartiles, especially for Q1 and Q2, during compared to before the SOE. The relative risk increases (95% CI) were Q1: -40.6% (-41.4% to -39.8%; p < 0.001), Q2: -34.0% (-34.7% to -33.3%; p < 0.001), Q3: -13.1% (-13.8% to -12.4%; p < 0.001), and Q4: -15.3% (-16.0% to -14.7%; p < 0.001), adjusted for sex, age, BMI, equivalent income adjusted for the number of household members, and educational level of parents. The interaction p was <0.001 for Q1-3 vs. Q4. Guardians with low total scores were significantly more likely to have less time, mental capacity, and financial ability to prepare meals after the SOE. Therefore, schoolchildren's meal quality deteriorated during the SOE, particularly among those with guardians with low food literacy even after adjustment for household income level and guardians' educational level.

Usefulness of Simple Meal Screening Using Dietary Assessment Sheets for Evacuation Shelters

To maintain the health of evacuees, meals provided at emergency shelters should be monitored and improvement measures should be taken where necessary. Time and human resources are limited during devastating disasters; thus, the authors have developed the Dietary Assessment Sheets for Evacuation Shelters. This study examines whether the quality of meals can be assessed using simple check items on the Dietary Assessment Sheets.

A total of 28 Dietary Assessment Sheets for 98 meals provided 16-19 days after the heavy rains in Kumamoto in July 2020 at 12 shelters were used in the analysis. Dietitians working for shelters were requested to fill the Dietary Assessment Sheets and food record sheets provided by the Prefectural Government. If any subitem was checkmarked, it was considered "checked," and if left blank, it was considered "not checked" and divided into categorical groups. Based on the food record sheets and meal photos, contents of energy, protein, and vitamins B₁, B₂, and C were calculated for each meal. Energy and nutrient contents were compared between the categorical groups.

The study revealed that nutritionally poor meals were characterized as those comprising only "Grain dishes," those that were not "Boxed meals," and those involving "Self-Defense Forces," "Dietitians," or "Others." Their energy, protein, and vitamin B₁, B₂, and C content was significantly lower than that of meals with marks on other checkboxes in the same category.

Shelters that provide these meals should be given priority for nutrition assistance due to their poor diets. The results imply that the Dietary Assessment Sheets could serve as a simple tool to determine the shelters that require nutritional assistance.

Changes in Selected Food Groups Consumption and Quality of Meals in Japanese School Children during the COVID-19 Pandemic

In 2020, a state of emergency was declared to control the devastating impact of coronavirus, leading to temporary school closures in Japan, meaning that school lunches were not provided to the majority of schoolchildren. Using questionnaires completed by participants' guardians, we examined the relationship between household income and the quality of meals in Japanese schoolchildren before, during, and after the state of emergency. Participants (1111 children, 10-14 years old) were chosen to form a nationally representative sample of the Japanese population. "Well-balanced dietary intake" was defined as the intake of (i) meat, fish, or eggs and (ii) vegetables. The desired prevalence was defined as equal to or more than twice a day. Household income was divided into quartiles. "Well-balanced dietary intake" was lower in all households during the state of emergency compared with before. The proportion of those with a "well-balanced dietary intake" at least twice a day was notably low in both Q3 and Q4 during the state of emergency compared with before the declared state of emergency; relative risk increase (95% CI) were Q1: -19.0% (-19.6% to -18.4%), p < 0.001, Q2: -21.3% (-22.1% to -20.6%) p < 0.001, Q3: -25.4% (-26.1% to -24.7%), p < 0.001, and Q4: -34.8% (-35.6% to -34.0%), p < 0.001. The interaction p (vs. Q1) of Q2, Q3, and Q4 were all <0.001. Guardians from low-income households had significantly higher rates of having less: time, psychological room, and financial position to prepare meals during the state of emergency. Our results suggest that schoolchildren's quality of meals worsened during the state of emergency, especially in low-income households, because school lunches were not provided.

Frequency of meals that includes staple, main and side dishes and nutrient intake: findings from the 2012 National Health and Nutrition Survey, Japan

OBJECTIVE

To investigate the relationship between nutrient intake and a straightforward Japanese nutritional goal of consuming a meal that includes staple, main and side dishes (SMS meal) more than twice a day.

DESIGN

This was a cross-sectional, observational study using the data from de-identified records of the 2012 National Health and Nutrition Survey. Dietary assessment was conducted using semi-weighed dietary records that were completed on one weekday.

SETTING

A home-based setting in Japan.

PARTICIPANTS

30 269 subjects (male n 14 284; female n 15 985) aged ≥6 years (6-103 years, mean 50·4 (sd 22·3) years).

RESULTS

As the frequency of SMS meals increased, we found a higher intake of most nutrients and each food group. Subjects who consumed SMS meals at least twice a day were more likely to meet the Dietary Reference Intakes (DRI) for Japan compared with subjects who consumed an SMS meal once a day or less. However, the frequency of SMS meals did not necessarily ensure that DRI for Japan for saturated fatty acid, vitamin A, vitamin B1, calcium, iron and salt were met.

CONCLUSIONS

Consuming SMS meals at least twice a day is a useful and straightforward nutrition goal to achieve adequate intake of some nutrients. However, it is necessary to provide the public with more information on foodstuff choice to ensure an adequate intake of all nutrients.

Frequency of consumption of balanced meals, bodyweight gain and incident risk of glucose intolerance in Japanese men and women: A cohort study

AIMS/INTRODUCTION

This cohort study assessed the risk for bodyweight gain and development of glucose intolerance based on the frequency of consumption of balanced meals including grain, fish or meat and vegetables.

MATERIALS AND METHODS

The participants (8,573 men, 3,327 women) were employees of a company in Japan. A self-administered questionnaire was used to evaluate the frequency of balanced meal consumption. Bodyweight changes and the incidence of glucose intolerance (glycated hemoglobin >6.0%) during the 3-year follow-up period were determined through annual health examinations.

RESULTS

The mean bodyweight change over a period of 3 years was 0.78 kg for men and 0.84 kg for women. A lower frequency of balanced meals was associated with a higher bodyweight gain for men (P for trend = 0.004), but not for women. During the study, 464 men and 115 women developed glucose intolerance. Overall, the frequency of balanced meals was not associated with the risk of glucose intolerance in either sex. However, the interaction between the frequency of balanced meals and degree of obesity had a significant effect on the incidence of glucose intolerance in men (P = 0.005), with less frequent consumption of balanced meals being associated with a higher risk for glucose intolerance among men with a BMI ≥25.0 kg/m2 (P for trend = 0.007).

CONCLUSIONS

A higher frequency of balanced meals, including grain, fish or meat and vegetable dishes - important components of healthy Japanese food - was associated with a lower risk of glucose intolerance in obese men, but not in non-obese men and women.

Impact of a Rice-Centered Diet on the Quality of Sleep in Association with Reduced Oxidative Stress: A Randomized, Open, Parallel-Group Clinical Trial

Previously, we found that a Japanese diet was associated with psychological status, and a combination of rice and miso was related to mental and physical health. We hypothesized that the intake of a rice-based diet affected mental and physical health and aimed to investigate the consequences of a dietary intervention with rice. We conducted a randomized, open-label, parallel-group clinical trial that included 60 participants, who were randomly assigned to receive either rice-based meals or meals with other cereals for three daily meals over 2 months. The participants were surveyed for psychological status and biochemical changes. Sleep quality index scores showed significant improvement after the rice-based intervention. Additionally, blood oxidative stress levels were reduced in the rice-diet group compared with the no-rice-diet group. Although the molecular mechanisms should be investigated in detail, our findings suggest that controlling oxidative stress through the intake of a rice-centered diet may be key to improving sleep quality.

Frequency of Balanced-Meal Consumption and Frailty in Community-Dwelling Older Japanese: A Cross-Sectional Study

BACKGROUND

Although meals that combine a staple food, main dish, and side dish (balanced meals) are recommended in Japan, the health effects of such meals are unclear. We investigated the association of frequency of eating balanced meals with frailty among community-dwelling older Japanese.

METHODS

We analyzed data from 912 persons aged 65 years or older who participated in the Hatoyama Cohort Study or Kusatsu Longitudinal Study. The frequency of eating two or more balanced meals daily was self-reported as ≤1 day/week, 2 or 3 days/week, 4 or 5 days/week, and daily. Frailty was defined as the presence of at least three, and pre-frailty as the presence of one or two, of the following criteria: weight loss, muscle weakness, exhaustion, slowness, and low physical activity. Adjusted logistic regression was used to study associations of frequency of balanced-meal consumption with frailty (prefrailty and frailty combined) and frailty criteria.

RESULTS

Participants reporting a frequency of balanced-meal consumption of ≤2 or 3 days/week had a higher prevalence of frailty (odds ratio [OR], 1.79; 95% confidence interval [CI], 1.21-2.64) than did those reporting a frequency of daily. Lower frequency of balanced-meal consumption was also associated with higher prevalences of weight loss (OR, 4.10; 95% CI, 1.90-8.85), exhaustion (OR, 6.35; 95% CI, 2.49-16.17), and low physical activity (OR, 1.92; 95% CI, 1.22-3.01).

CONCLUSIONS

Our findings suggest that more frequent twice daily consumption of meals with a staple food, main dish, and side dish decreases the risks of prefrailty and frailty.

Mediators of the effects of rice intake on health in individuals consuming a traditional Japanese diet centered on rice

Although the Japanese diet is believed to be balanced and healthy, its benefits have been poorly investigated, especially in terms of effects on mental health. We investigated dietary patterns and physical and mental health in the Japanese population using an epidemiological survey to determine the health benefits of the traditional Japanese diet. Questionnaires to assess dietary habits, quality of life, sleep quality, impulsivity, and depression severity were distributed to 550 randomly selected middle-aged and elderly individuals. Participants with any physical or mental disease were excluded. Two-hundred and seventy-eight participants were selected for the final statistical analysis. We determined rice to be one of the most traditional foods in Japanese cuisine. Scores for each questionnaire were computed, and the correlations between rice intake and health indices were assessed. When analyzing the direct correlations between rice intake and health indices, we found only two correlations, namely those with quality of life (vitality) and sleep quality. Path analysis using structural equation modeling was performed to investigate the association between rice intake and health, with indirect effects included in the model. Additional associations between rice intake and health were explained using this model when compared to those using direct correlation analysis. Path analysis was used to identify mediators of the rice-health association. These mediators were miso (soybean paste) soup, green tea, and natto (fermented soybean) intake. Interestingly, these mediators have been major components of the Japanese diet since 1975, which has been considered one of the healthiest diets since the 1960s. Our results indicate that the combination of rice with other healthy foods, which is representative of the traditional Japanese diet, may contribute to improvements in physical and mental health.