The Japanese Journal of Nutrition and Dietetics
Online ISSN : 1883-7921
Print ISSN : 0021-5147
ISSN-L : 0021-5147
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Showing 1-5 articles out of 5 articles from the selected issue
Original Articles
  • Etsuko Kibayashi
    Type: Original Article
    2021 Volume 79 Issue 2 Pages 53-63
    Published: April 01, 2021
    Released: May 15, 2021

    Objective: To identify changes in self-efficacy and the association between self-efficacy and stage of behavior change based on readiness to improve diet in a 3-year-follow-up high-school study.

    Methods: From among 320 students entering high school A in Hyogo Prefecture in 2012, we analyzed 225 from whom responses were obtained throughout 2012 to 2014, excluding students enrolled in a specialized home economics course. Self-efficacy was evaluated on a five-point scale of whether or not students thought that they could improve their diets. Changes in self-efficacy and stages of behavior change were examined by the Friedman test, and the association between the two in the students' third year was analyzed by covariance structure analysis. Binomial logistic regression analysis was subsequently performed with a 12-item self-efficacy scale developed to examine the validity of self-efficacy as the dependent variable and adjusting for sex.

    Results: Over the 3 years, the numbers of males responding "I think I can improve my diet" and "I can improve my diet" decreased, and the number of males in the precontemplation stage increased. Among girls, neither variable changed significantly. Covariance structure analysis indicated a significant positive path from self-efficacy to stage of behavior change. Logistic regression analysis showed a significantly higher odds ratio for low self-efficacy scores in the precontemplation stage relative to the preparation, action, and maintenance stages.

    Conclusion: Scores for self-efficacy and stage of behavior change based on readiness to improve diet declined only in boys. Enhanced educational support and an environment fostering self-efficacy should help improve diet.

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  • Yuka Nishida, Kanae Ideguchi, Asami Maeda
    Type: Original Article
    2021 Volume 79 Issue 2 Pages 64-75
    Published: April 01, 2021
    Released: May 15, 2021

    Objective: The purpose of this study was to investigate the relationship between the time of meal intake and mineral metabolism, and to examine the effects on urinary mineral excretion and rhythm when only the time of supper was changed.

    Methods: Urine samples were collected from ten young adult women with no renal dysfunction under two feeding times: "early supper" at 18:30, and "late supper" at 23:30. The diet and water consumption were unified from 17:00 on the day before the experiment, and 24-hour urine was collected from 6:30 in the morning to 6:30 the next morning at two-hour intervals (six hours at night). Urinary sodium, potassium, phosphorus, calcium, magnesium, and creatinine concentrations were measured, and diurnal variations in urinary mineral excretion (creatinine-corrected value) and urinary excretion during six hours after each meal were examined.

    Results: In the late supper, the urinary excretion of potassium and phosphorus (creatinine-corrected value) at 6:30 the next morning (from 24:30 to 6:30 the next morning) was significantly lower than that in the early supper (potassium, p =  0.002; phosphorus, p = 0.006). The 12-hour urinary excretion of sodium and potassium from 18:30 to 6:30 the next morning was significantly lower in the late supper than in the early supper (sodium, p = 0.025; potassium, p =  0.030). Urinary excretion of calcium and magnesium showed a pattern depending on the postprandial time, regardless of the feeding time.

    Conclusion: Sodium and potassium are not excreted in urine, and tend to accumulate in the body when supper is consumed late at night. In the prevention of hypertension and dietary management of renal failure, it is important not to delay supper time.

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Brief Reports
  • Chinatsu Tobari, Masako Takamasu
    Type: Brief Report
    2021 Volume 79 Issue 2 Pages 76-89
    Published: April 01, 2021
    Released: May 15, 2021

    Objective: This study aimed to understand the status of dietary lifestyles and beverage consumption among university students in Malaysia and to identify their characteristics.

    Methods: Dietary lifestyle and beverage consumption surveys were conducted between March and April 2019 with 632 students from MARA University of Technology (Universiti Teknologi MARA:UiTM) Dungun in Terengganu State and UiTM Puncak Alam in Selangor State, Malaysia. The questionnaire responses of the dietary lifestyle survey were scored, and the Mann-Whitney U test was used to compare the differences between groups, between male and female students as well as between universities. The results of the beverage consumption survey were tabulated by item, and a χ2 test was conducted.

    Results: The dietary lifestyle survey revealed that all subjects understood the relationship between exercise and health and the importance of eating habits. However, they lacked knowledge related to sugar intake. Moreover, the subjects skipped more breakfasts than lunches or dinners. Female students demonstrated a high awareness of sugar intake and a strong interest in nutrition education workshops, while male students tended to be interested and actively engaged in exercise. The beverage consumption survey revealed a high water consumption frequency among all subjects. Furthermore, the frequency of consuming sugar-sweetened beverages (SSB), such as black tea with condensed milk or sugar and malted beverages, was high. Female students consumed sugar-free beverages less frequently than male students.

    Conclusion: Issues related to sugar intake and SSB consumption frequency among student subjects became evident in the present study.

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Practical Solutions
  • Aki Sato, Shinya Masaki, Moeri Umemoto, Hiroki Yamamoto, Masahito Oyam ...
    Type: Practical Solution
    2021 Volume 79 Issue 2 Pages 90-102
    Published: April 01, 2021
    Released: May 15, 2021

    Objective: Eating disorders (EDs) are intractable diseases that frequently occur in young girls. The priority in their treatment is to improve nutrition. Autism spectrum disorder (ASD) is associated with EDs in 10 to 20% of cases, and their prognosis is often poor. In treatment, it is necessary to focus on the characteristics of ASD. We report on the implementation of nutrition counseling focusing on the characteristics of ASD as part of team medical care for two patients with ASD who were hospitalized for EDs.

    Methods: Two 15-year-old girls with ASD were admitted to a psychiatric hospital for treatment of EDs. Case 1 was an aesthetic athlete who was hospitalized due to low body weight caused by excessive exercise and dietary restrictions. Case 2 presented an anorexic reaction to stress, who was hospitalized for rapid weight loss due to anorexia. The registered dietitian focused on the characteristics of ASD and provided nutritional counseling based on 1) understanding and praise, 2) use of visual information, and 3) repetition of specific explanations.

    Results: In Case 1, the patient's goal weight was achieved by decreasing her activity level and consuming all her provided food, which increased every week. In case 2, anorexia subsided, and the target weight was achieved.

    Conclusion: In two cases with EDs and ASD, the usefulness of nutritional guidance based on 1) understanding and praise, 2) use of visual information, and 3) repetition of specific explanations was suggested.

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  • Goichiro Yoshida, Akane Iwama, Minori Sakata (Toyomichi), Natsumi Naka ...
    Type: Information
    2021 Volume 79 Issue 2 Pages 103-111
    Published: April 01, 2021
    Released: May 15, 2021

    Objective: This study aimed to investigate the fluid balance of top canoe sprint athletes during training in different seasons and examine seasonal differences in controlling energy expenditure.

    Methods: We examined the fluid balance of top-level university canoe sprint athletes during practice over three days in spring, summer, and winter. Concurrently, energy expenditure during practice was measured using the heart rate method. We examined seasonal differences in the amount of sweating, sweating ratio, water consumption, and water consumption ratio obtained for each season using an analysis of covariance with energy expenditure as the covariate.

    Results: For individual kayak practice sessions, each item related to fluid balance was approximately twice as high in summer as in winter. Energy expenditure was only low during winter. When the effect of energy expenditure was adjusted for each fluid balance item and seasonal differences were examined, the values of sweating amount and ratio were significantly higher (p  < 0.001) in the order of summer, spring, and winter. Other differences were also observed between seasons. There was a seasonal difference (p  < 0.001) in the amount and ratio of water consumption, which showed high values ​during summer. The hydration ratio during practice was 61% in spring, 54% in summer, and 68% in winter, indicating the need for hydration following practice in all seasons.

    Conclusions: These results suggest that for top-level university canoe sprint athletes, the seasonal differences in fluid balance during practice can be examined by adjusting the effects of energy expenditure.

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