Hitomi Okubo

Dietary fiber intake, dietary glycemic index and load, and body mass index: a cross-sectional study of 3931 Japanese women aged 18-20 years.

Objective:Few observational studies have investigated dietary fiber intake and dietary glycemic index (GI) and glycemic load (GL) simultaneously in relation to obesity, particularly in non-Western populations. We examined the associations between dietary fiber intake and dietary GI and GL, and body mass index (BMI) in young Japanese women.Design:Cross-sectional study.Subjects:A total of 3931 female Japanese dietetic students aged 18–20 years from 53 institutions in Japan.Methods:Dietary fiber intake and dietary GI and GL (GI for glucose=100) were assessed by a validated, self-administered, diet history questionnaire. BMI was calculated from self-reported body weight and height.Results:Mean values of BMI, dietary fiber intake, dietary GI and dietary GL were 21.0 kg/m2, 6.5 g/4186 kJ, 65.1 and 82.1/4186 kJ, respectively. White rice (GI=77) was the major contributor to dietary GI and GL (45.8%). After controlling for potential dietary and nondietary confounding factors, dietary fiber intake was negatively correlated with BMI (adjusted mean=21.1 kg/m2 in the lowest and 20.7 kg/m2 in the highest quintiles; P for trend=0.0007). Conversely, dietary GI and GL were independently positively correlated with BMI (20.8 and 21.2 kg/m2; P for trend=0.03, and 20.5 and 21.5 kg/m2; P for trend=0.0005, respectively).Conclusions:Dietary fiber intake showed an independent negative association with BMI, and dietary GI and GL showed an independent positive association with BMI among relatively lean young Japanese women.

Validation of self-reported energy intake by a self- administered diet history questionnaire using the doubly labeled water method in 140 Japanese adults

Objective:To validate reported energy intake (rEI) with a self-administered diet history questionnaire (DHQ) against total energy expenditure (TEE) by the doubly labeled water (DLW) method.Subjects:A total of 140 healthy Japanese adults (67 men and 73 women) aged 20–59 years living in four areas in Japan.Methods:Energy intake was assessed twice with DHQ over a 1-month period before and after TEE measurement (rEIDHQ1 and rEIDHQ2, respectively). TEE was measured by DLW during 2 weeks (TEEDLW).Results:Mean rEIDHQ1 was lower than those of TEEDLW by 1.9±2.4 MJ/day (16.4%, P<0.001) for men and 0.6±1.9 MJ/day (6.0%, P<0.01) for women. In men and women together, 62 subjects (44%) were defined as underreporters (rEIDHQ1/TEEDLW <0.84), 58 (41%) as acceptable reporters (0.84–1.16) and 20 (14%) as over-reporters (>1.16). Pearson correlation coefficient was 0.34 for men and 0.22 for women. After adjustment for the dietary and non-dietary factors related to rEIDHQ1/TEEDLW, the correlation coefficient improved to 0.42 and 0.37, respectively.Conclusion:The energy intake assessed with DHQ correlated low to modestly with TEE measured by DLW. In addition, DHQ underestimated energy intake at a group level. Caution is needed when energy intake was evaluated by DHQ at both individual and group levels.

Physical activity level in healthy free-living Japanese estimated by doubly labelled water method and International Physical Activity Questionnaire

Objective:To measure total energy expenditure (TEE) for normal healthy Japanese by the doubly labelled water (DLW), and to compare the physical activity level (PAL) among categories classified by the categories used in daily reference intake (DRI), Japan and the International Physical Activity Questionnaire (IPAQ).Subjects and methods:A total of 150 healthy Japanese men and women aged 20- to 59-year-old living in four districts of Japan. TEE was measured by the DLW method, and the PAL was calculated from TEE divided by basal metabolic rate. Simultaneously with TEE measurement, the PAL was assessed employing the categories used in DRI, Japan and IPAQ.Results:The average TEE and PAL were 10.78±1.67 MJ/day and 1.72±0.22 for males and 8.37±1.30 MJ/day and 1.72±0.27 for females, respectively. The subjects in the highly active categories assessed by both DRI and IPAQ showed significantly higher PAL compared with less active categories. However, PALs among light and moderate categories by DRI, and insufficient and sufficiently active by IPAQ were not significantly different.Conclusions:In developed countries, highly active subjects could be assessed by a simple questionnaire. However, the questionnaire should be improved to clarify the sedentary to moderately active subjects by assessing carefully very light to moderate physical activity.

Association between dietary fiber, water and magnesium intake and functional constipation among young Japanese women

Objective:Most research on constipation has focused on dietary fiber intake. Here, we examined the intake of water and magnesium, nutrients possibly associated with constipation, as well as that of dietary fiber in relation to constipation.Design:Cross-sectional study.Subjects:A total of 3835 female Japanese dietetic students aged 18–20 years from 53 institutions in Japan.Methods:Dietary intake was estimated with a validated, self-administered diet history questionnaire. Functional constipation was defined using the Rome I criteria.Results:The prevalence of functional constipation was 26.2%. Neither dietary fiber intake (mean=6.4 g/4186 kJ) nor intakes of total water and water from fluids were associated with constipation. Conversely, low intake of water from foods was associated with an increasing prevalence of constipation. In comparison with women in the first (lowest) quintile, the multivariate adjusted odds ratio (OR) (95% confidence interval (CI)) for women in the second, third, fourth, and fifth quintiles were 0.72 (0.57, 0.90), 0.78 (0.62, 0.98), 0.71 (0.56, 0.89), and 0.77 (0.61, 0.97), respectively (P for trend=0.04). Additionally, low magnesium intake was associated with increasing prevalence of constipation. Compared with women in the first quintile, the multivariate adjusted OR (95% CI) for women in the second, third, fourth and fifth quintiles were 0.70 (0.56, 0.88), 0.75 (0.60, 0.95), 0.73 (0.58, 0.92) and 0.79 (0.63, 0.996), respectively (P for trend=0.09).Conclusions:Low intakes of water from foods and magnesium are independently associated with an increasing prevalence of functional constipation among a population whose dietary fiber intake is relatively low.

Monetary costs of dietary energy reported by young Japanese women: association with food and nutrient intake and body mass index.

OBJECTIVE Little is known about the relationship of monetary diet costs to dietary intake and obesity, particularly in non-Western populations. This study examined monetary cost of dietary energy in relation to diet quality and body mass index (BMI) among young Japanese women. DESIGN Dietary intake was assessed by a validated, self-administered, diet history questionnaire. Diet costs were estimated using retail food prices. Monetary cost of dietary energy (Japanese yen 1000 kcal-1) was then calculated. BMI was computed from self-reported body weight and height. SUBJECTS A total of 3931 female Japanese dietetic students aged 18-20 years. RESULTS Monetary cost of dietary energy was positively associated with intakes of fruits, vegetables, fish and shellfish, and pulses; however, higher monetary cost of dietary energy was also associated with higher consumption of fat and oil, meat and energy-containing beverages, and lower consumption of cereals (rice, bread and noodles) (all P for trend <0.01). At the nutrient level, monetary cost of dietary energy was positively associated with intakes of dietary fibre and key vitamins and minerals, but also associated positively with intakes of fat, saturated fatty acids, cholesterol and sodium, and negatively with carbohydrate intake (all P for trend <0.0001). After adjustment for possible confounders, monetary cost of dietary energy was quite weakly but significantly negatively associated with BMI (P for trend = 0.0197). CONCLUSIONS Increasing monetary cost of dietary energy was associated with both favourable and unfavourable dietary intake patterns and a quite small decrease in BMI in young Japanese women.

Dietary intake in relation to self-reported constipation among Japanese women aged 18–20 years

Objective:Information on modifiable lifestyle factors associated with constipation is limited, especially among non-Western populations. We examined associations between dietary intake and self-reported constipation in young Japanese women.Design:Cross-sectional study.Subjects:A total of 1705 female Japanese dietetic students aged 18–20 years and free of current disease and current dietary counseling.Methods:Dietary intake was estimated over a 1-month period with a validated, self-administered, diet history questionnaire, and lifestyle variables including self-reported constipation were assessed by a second questionnaire designed for this survey.Results:A total of 436 women (26%) reported themselves to be ‘constipated’. A multivariate odds ratio (OR) for women in the highest quartile of rice intake was 0.47 (95% confidence interval (CI): 0.33, 0.68) compared with the lowest. Additionally, women in the highest category of coffee intake had a multivariate OR of 0.67 (0.47, 0.94) compared with women in the lowest. Conversely, women in the highest quartile of confectionery intake had a multivariate OR of 1.54 (1.12, 2.13) compared with women in the lowest. Moreover, a multivariate OR for constipation for women in the highest quartile of Japanese and Chinese tea intake was 1.49 (1.09, 2.05) compared with women in the lowest. Neither total dietary fiber intake nor other lifestyle factors examined were associated with constipation.Conclusions:The consumption of rice and coffee was inversely associated with and that of confectioneries and Japanese and Chinese tea was positively associated with a prevalence of self-reported constipation.

Neighborhood socioeconomic status in relation to dietary intake and body mass index in female Japanese dietetic students

OBJECTIVE An increasing number of studies conducted in Western countries have shown that living in a socioeconomically disadvantaged neighborhood is associated with unfavorable dietary intake patterns and an unfavorable health status. However, information on such neighborhood socioeconomic differences in diet and health among different cultural settings, including Japan, is absolutely lacking. This cross-sectional study examined the association of neighborhood socioeconomic status (SES) with dietary intake and body mass index (BMI) in a group of young Japanese women. METHODS Subjects were 3892 female Japanese dietetic students 18-20 y of age from 53 institutions, residing in 1033 municipalities in 47 prefectures in Japan. Neighborhood SES index was defined by seven municipal-level variables, namely unemployment, household overcrowding, poverty, education, income, home ownership, and vulnerable groups, with an increasing index signifying increasing neighborhood socioeconomic disadvantage. Dietary intake was estimated using a validated, comprehensive self-administered diet history questionnaire. BMI was computed from self-reported body weight and height. RESULTS Neighborhood SES index was not materially associated with most of the dietary variables. However, neighborhood SES index was positively associated with BMI, with significance (P for trend=0.020). This significant association remained after adjustment for potential confounding or mediating factors including household SES, dietary, other lifestyle, and geographic factors (P for trend=0.037). CONCLUSION Although no material association was seen between neighborhood SES and dietary intake, increasing neighborhood socioeconomic disadvantage was independently associated with increasing BMI in a group of young Japanese women.

Relationship between soy and isoflavone intake and periodontal disease: The Freshmen in Dietetic Courses Study II

BackgroundMuch research has shown that soy products inhibited various diseases. However, no published studies have examined the effects of consumption of soy and isoflavones on periodontal disease. The aim of this study was to investigate whether soy and isoflavone intake is associated with the prevalence of periodontal disease.MethodsThe subjects were 3956 Japanese female students, aged 18 to 22 years, who were taking a dietetic course. Periodontal disease was defined as present when a subject reported diagnosis of the disorder by a dentist. Information on dietary factors was collected using a validated diet history questionnaire. Logistic regression analysis was used to estimate the odds ratios and their confidence intervals of periodontal disease. Adjustment was made for cigarette smoking, toothbrushing frequency, region of residence, and body mass index.ResultsThe prevalence of periodontal disease was 8.0%. Intake of total soy product and tofu was independently associated with a decreased prevalence of periodontal disease; multivariate odds ratios in comparison of the highest with the lowest quintile were 0.68 and 0.68, respectively (95% confidence intervals = 0.47–0.97 and 0.47–0.98, P for trend = 0.01 and 0.004, respectively). A significant inverse dose-response relationship between the intake of isoflavones and the prevalence of periodontal disease was observed, although the difference in the adjusted odds ratio between the extreme quintiles was of borderline significance (P for trend = 0.04). There were no measurable dose-response relationships between consumption of tofu products, fermented soybeans, boiled soybeans, miso, or miso soup and the prevalence of periodontal disease.ConclusionOur findings suggest that soy and isoflavone intake may decrease the likelihood of periodontal disease. Further investigations with objective measures for periodontal disease are needed to confirm our findings.

Dairy food, calcium and vitamin D intake and prevalence of allergic disorders in pregnant Japanese women.

SETTING Epidemiological evidence for the associations between intake of dairy products, calcium and vitamin D and allergic disorders has been inconsistent. OBJECTIVES To examine such associations in Japan. DESIGN This cross-sectional study enrolled 1745 pregnant women. The definitions of wheeze and asthma were based on European Community Respiratory Health Survey criteria, whereas those of eczema and rhinoconjunctivitis were based on International Study of Asthma and Allergies in Childhood criteria. Information on dietary factors was collected using a validated self-administered diet history questionnaire. RESULTS Intake of total dairy products, milk, yoghurt, cheese and calcium was not related to the prevalence of wheeze, asthma, eczema or rhinoconjunctivitis. After adjustment for potential confounders, vitamin D intake was found to be independently positively associated with the prevalence of asthma: the adjusted ORs for asthma in the first, second, third and fourth quartiles were respectively 1.00 (reference), 1.26 (95%CI 0.65-2.50), 2.08 (95%CI 1.13-3.94), and 1.82 (95%CI 0.97-3.51, P for trend = 0.03). There were no relationships between vitamin D consumption and the prevalence of wheeze, eczema or rhinoconjunctivitis. CONCLUSIONS These findings suggest that vitamin D intake may be positively related to the prevalence of asthma in young adult Japanese women.

Calcium intake during pregnancy is associated with decreased risk of emotional and hyperactivity problems in five-year-old Japanese children

ABSTRACTBackground: Recently, more attention has been paid to behavioral problems in children. However, for the most part, risk factors for these problems have yet to be determined.Objective: The c...