A semi-quantitative food frequency questionnaire (FFQ) comprising a small number of food items may allow for more accurate assessment of habitual dietary intake in Japanese collegiate athletes. This study aimed to evaluate the validity and reproducibility of a commercially available FFQ (FFQg) with a newly added protein supplement item for assessing habitual dietary intake compared to the 24-hour dietary recall (24hDR) method using multiple statistical tests. A total of 108 participants (46 males) completed the FFQg on two separate days (FFQg1 and FFQg2) and 24hDRs on three non-consecutive days (two weekdays and one weekend day). Percentage differences, cross-classification analysis by quintile and Spearman’s rank correlation coefficients (CCs) were calculated to evaluate the validity and reproducibility of the FFQg. Results showed median percentage differences and de-attenuated CCs between the FFQg2 and 24hDRs were -3.4 (range: -46.8 - 25.1) and 0.33 (0.03 - 0.55), respectively, for 34 nutrients, and -16.1 (-51.4 - 45.0) and 0.34 (0.03 -0.64), respectively, for 18 food groups. Cross-classification analysis showed that median proportions of the “completely opposite category” between FFQg2 and 24hDRs for energy-adjusted intakes of nutrients and food groups were both within 5%. Median CCs for energy-adjusted intake between the FFQ1 and FFQ2 were 0.61 (0.40 - 0.82) for nutrients and 0.52 (0.40 - 0.87) for food groups. In conclusion, although estimating habitual dietary intake requires careful consideration, the FFQg offers reasonably valid measurements of ranking individuals to assess intakes of macronutrients and food groups in collegiate athletes, with a relatively good reproducibility.

Background High dietary non-enzymatic antioxidant capacity (NEAC) has been inversely related to the incidence of degenerative diseases. However, few studies have investigated the validity and reproducibility of dietary NEAC estimated from a food frequency questionnaire (FFQ). We assessed the validity and reproducibility of FFQ-based dietary NEAC against a dietary record (DR). Methods Participants were 244 men and 253 women who completed a 28-day DR and FFQs. NEAC for each food item was estimated according to available databases of antioxidant capacity, as measured by ferric reducing-antioxidant power (FRAP), oxygen radical absorbance capacity (ORAC), and total radical-trapping antioxidant parameter (TRAP). Using Spearman’s rank correlation coefficients (CCs), we assessed the validity for dietary NEACs from a 28-day DR and a FFQ, and the reproducibility for them from two FFQs administered at a 1-year interval. Additionally, joint classification and the Bland-Altman method were applied to assess agreement between the two methods. Results Regarding validation, deattenuated CCs for the energy-adjusted overall dietary NEACs between FFQ and DR for FRAP, ORAC, and TRAP were 0.52, 0.54, and 0.52, respectively, for all subjects. Extreme miscategorization rates by joint classification analysis were 2% for FRAP and ORAC and 1% for TRAP. Regarding reproducibility, CCs between the energy-adjusted dietary NEACs from two FFQs were 0.64 for FRAP and 0.65 for ORAC and TRAP. Conclusion The validity and reproducibility of dietary NEAC of total food from the FFQ were moderate. Estimations of dietary NEAC using FFQ would be useful in studying disease relationships by categorizing habitual dietary NEAC.

Background: Cruciferous vegetables, a rich source of isothiocyanates, have been reported to lower the risk of several types of cancer, including lung cancer. However, evidence from prospective observations of populations with a relatively high intake of cruciferous vegetables is sparse.Objective: We investigated the association between cruciferous vegetable intake and lung cancer risk in a large-scale population-based prospective study in Japan.Methods: We studied 82,330 participants (38,663 men; 43,667 women) aged 45-74 y without a past history of cancer. Participants were asked to respond to a validated questionnaire that included 138 food items. The association between cruciferous vegetable intake and lung cancer incidence was assessed with the use of Cox proportional hazard regression analysis to estimate HRs and 95% CIs (with adjustments for potential confounding factors).Results: After 14.9 y of follow-up, a total of 1499 participants (1087 men; 412 women) were diagnosed with lung cancer. After deleting early-diagnosed cancer and adjusting for confounding factors, we observed a nonsignificant inverse trend between cruciferous vegetable intake and lung cancer risk in men in the highest compared with the lowest quartiles (multivariate HR: 0.85; 95% CI: 0.69, 1.06; P-trend = 0.13). Stratified analysis by smoking status revealed a significant inverse association between cruciferous vegetable intake and lung cancer risk among those who were never smokers and those who were past smokers after deleting lung cancer cases in the first 3 y of follow-up [multivariate HR for never smokers: 0.49 (95% CI: 0.27, 0.87; P-trend = 0.04); multivariate HR for past smokers: 0.59 (95% CI: 0.35, 0.99; P-trend = 0.10)]. No association was noted in men who were current smokers and women who were never smokers.Conclusion: This study suggests that cruciferous vegetable intake may be associated with a reduction in lung cancer risk among men who are currently nonsmokers.

Studies examining the impact of menstrual cycle phases on the cardiac autonomic nervous system have produced inconsistent results. This study aimed to investigate this relationship, controlling for the confounding effects of diet, physical activity, and sleep, which can be affected by the menstrual cycle. Fifteen female college students with regular menses were enrolled. Data regarding 24-h heart rate variability (HRV), dietary intake, eating behavior, menstrual distress, and sleep and activity parameters were obtained during the follicular and luteal phases. Power spectral analysis of HRV was used to calculate low-frequency (0.04-0.15 Hz, LF), high-frequency (>0.15 Hz, HF), and total spectral power (TP). Cardiac sympathetic and parasympathetic nervous system activity indicators were evaluated as LF/HF and HF/TP, respectively. Intake of protein and fat, as well as total sleep time and number of awakenings, were higher in the luteal phase than in the follicular phase (p<0.05). Tendencies for increased mean activity counts, emotional eating scores, and behavioral change scores in the Menstrual Distress Questionnaire were observed in the luteal phase (p<0.10). Although LF/HF was higher in the luteal phase (p=0.036), the relationship was weakened after controlling for diet, physical activity, and sleep (p=0.113). Our findings suggest that altering sympathetic nervous system activity during the menstrual cycle was not independent from major lifestyle factors (diet, physical activity, and sleep). Menstrual cycle phase and changes of these parameters should be considered when assessing the cardiac autonomic function among menstruating woman.

Background: Food frequency questionnaires (FFQs) have been developed and validated for various populations. To our knowledge, however, no FFQ has been validated for young athletes. Here, we investigated whether an FFQ that was developed and validated to estimate dietary intake in middle-aged persons was also valid for estimating that in young athletes.Methods: We applied an FFQ that had been developed for the Japan Public Health Center-based Prospective Cohort Study with modification to the duration of recollection. A total of 156 participants (92 males) completed the FFQ and a 3-day non-consecutive 24-hour dietary recall (24hDR). Validity of the mean estimates was evaluated by calculating the percentage differences between the 24hDR and FFQ. Ranking estimation was validated using Spearman's correlation coefficient (CC), and the degree of miscategorization was determined by joint classification.Results: The FFQ underestimated energy intake by approximately 10% for both males and females. For 35 nutrients, the median (range) deattenuated CC was 0.30 (0.10 to 0.57) for males and 0.32 (-0.08 to 0.62) for females. For 19 food groups, the median (range) deattenuated CC was 0.32 (0.17 to 0.72) for males and 0.34 (-0.11 to 0.58) for females. For both nutrient and food group intakes, cross-classification analysis indicated extreme miscategorization rates of 3% to 5%.Conclusions: An FFQ developed and validated for middle-aged persons had comparable validity among young athletes. This FFQ might be useful for assessing habitual dietary intake in collegiate athletes, especially for calcium, vitamin C, vegetables, fruits, and milk and dairy products.

This cross-sectional study explored the prevalence of iron deficiency (ID) and associations between dietary factors and incidence of ID in female rhythmic gymnasts during preseason periods. Participants were 60 elite collegiate rhythmic gymnasts (18.1 ± 0.3 years [M ± SD]) who were recruited every August over the course of 8 years. Participants were divided into 2 groups according to the presence or absence of ID. Presence of ID was defined either by ferritin less than 12 μg/L or percentage of transferrin saturation less than 16%. Anthropometric and hematologic data, as well as dietary intake, which was estimated via a semiquantitative food frequency questionnaire, were compared. ID was noted in 48.3% of participants. No significant group-dependent differences were observed in physical characteristics, red blood cell counts, hemoglobin, hematocrit, haptoglobin, or erythropoietin concentrations. The ID group had a significantly lower total iron-binding capacity; serum-free iron; percentage of transferrin saturation; ferritin; and intake of protein, fat, zinc, vitamin B2, vitamin B6, beans, and eggs but not iron or vitamin C. The recommended dietary allowance for intake of protein, iron, zinc, and various vitamins was not met by 30%, 90%, 70%, and 22%-87% of all participants, respectively. Multiple logistic analysis showed that protein intake was significantly associated with the incidence of ID (odds ratio = 0.814, 95% confidence interval [0.669, 0.990], p = .039). Participants in the preseason's weight-loss periods showed a tendency toward insufficient nutrient intake and were at a high risk for ID, particularly because of lower protein intake.

Objectives Our study examines differences in eating behaviour between day workers and rotating shift workers, and considers whether diurnal preference could explain the differences. Methods Japanese female nurses were studied (39 day workers and 123 rotating shift workers, aged 21–63 years) using self-administered questionnaires. The questionnaires assessed eating behaviours, diurnal preference and demographic characteristics. The questionnaire in the Guidelines for the management of obesity disease issued by the Japan Society for the Study of Obesity was used to obtain scores for the levels of obesity-related eating behaviours, including cognition of constitution, motivation for eating, eating as a diversion, feeling of satiety, eating style, meal contents and temporal eating patterns. The Japanese version of the Morningness–Eveningness (ME) questionnaire was used to measure self-rated preference for the degree to which people prefer to be active in the morning or the evening (ME). Results The scores for meal contents and temporal eating patterns in rotating shift workers were significantly higher than those in day workers. The ME score of rotating shift workers was significantly lower, indicating greater eveningness/less morningness among rotating shift workers. Multivariate linear regression revealed that the ME score was significantly negatively associated with temporal eating patterns and showed a negative association with the score for meal contents at a trend level, while current work shift was not significantly correlated with the scores. Conclusions These results suggest that eating behaviours for rotating shift workers are associated with a more unbalanced diet and abnormal temporal eating patterns and that the associations may be explained by diurnal preference rather than by rotating shift work.

Strenuous exercise induces upper respiratory tract infection (URTI), whereas moderate exercise prevents URTI. This study aimed to assess the incidence of URTI and the association between URTI episodes and exercise duration in Japanese collegiate athletes. A cross-sectional survey was conducted with 1,740 participants; 1,235 responses were eligible for analysis. Participants were classified into three groups: control group (weekly total exercise duration <60 min, n=405), exercise group (weekly total exercise duration >60 min, n=193), and athlete group (joined a sports club and weekly exercise frequency >5 days, n=637). We requested the following information from participants: basic characteristics, incidence of URTI symptoms (fever, runny or plugged nose, sore throat, and cough) or influenza for each month over the past year, day of the week exercise is typically performed, and duration of exercise per week. The incidence of URTI episodes per year was significantly lower in the athlete group (2.0 ± 2.4 episodes) compared to the control group (2.6 ± 2.4 episodes, p<0.001). The incidence of URTI episodes did not significantly differ between the control group and exercise group (2.9 ± 2.9 episodes, p=0.607). Although the frequency of URTI episodes and exercise duration were not significantly associated among male athletes (p=0.209), they were positively associated in female athletes (p=0.027). These results indicate that Japanese collegiate athletes experience fewer URTI episodes than non-athletes, but athletes who exercise for long durations may frequently experience URTI, particularly female athletes.

Abstract Objective The present study aimed to investigate the correlation between mothers’ and children’s vegetable intake and whether children are conscious about their vegetable intake. Design Cross-sectional study. Self-administered questionnaires for mothers and children, consisting of items regarding diet history, were distributed to children via homeroom teachers. We created dummy exposure variables for each quartile of mothers’ vegetable intake. Multiple regression analysis was performed with children’s vegetable intake as the outcome variable. Setting Two public elementary schools in a residential district of Tokyo, Japan. Subjects Study participants were upper-grade children (aged 10–12 years) and their mothers (332 pairs of mothers and children). Results The mean vegetable intake in mothers and children was 310 (sd 145) g/d and 276 (sd 105) g/d, respectively. A positive linear relationship was found between mothers’ and children’s vegetable intake even after adjustment for considerable covariates (P<0·001). When stratified by children’s consciousness, the positive linear relationship was more pronounced in children who were conscious of eating all their vegetables (P<0·001 for interaction with children’s consciousness). Conclusions Mothers’ vegetable intake was significantly correlated with children’s vegetable intake. However, this correlation was stronger in children who were conscious of eating all their vegetables. Our findings suggest that enhancing mother’s vegetable intake and health consciousness of children are indispensable prerequisites for increasing vegetable intake among children.

The purpose of this study was to assess the effects of egg white (E) protein supplementation on the muscle damage indices and muscular soreness after acute resistance training (RT) compared with soy (S) or no protein supplementation (C). In this cross-over study, six healthy untrained men completed three RT trials. Participants were asked to consume a meat-free diet and refrain from high-intensity activities during all trial periods. On the day of RT, participants ingested one of three test beverages containing water only or water containing either 20 g of E or S protein 1.5 hours after breakfast, then performed 60 minutes of RT. Blood was drawn at baseline, before, immediately after, and 30 minutes after RT to assess blood glucose, lactate, insulin, growth hormone (GH), creatine kinase activity (CK) and cortisol levels. Urinary 3-methylhistidine (3-MetHis), urea nitrogen (UN), and creatinine (CRE) were measured using 24-h urine samples, and muscular soreness was measured by a visual analog scale. The daily protein intake was approximately 0.8 g/kg body weight in all three groups. Each lactate, GH, CK, cortisol, 3-MetHis, or muscular soreness increased significantly after RT, with no significant differences between the three groups. The UN was significantly higher in the E and S groups compared to the C group. The RT exercise protocol successfully induced blood biochemical changes, muscle damage or muscle soreness in all three groups with no significant differences, and pre-exercise protein supplementation taken in excess may accelerate protein catabolism.

ObjectiveHigher body mass index (BMI) values have been reported in rotating shift workers compared with regular daytime workers. This study examines the relationship between work schedule and BMI, and considers whether lifestyle habits could explain the relationship.MethodsJapanese female nurses (1179 day workers and 1579 rotating shift workers, aged 20-59) were studied using self-administered questionnaires. The questionnaires assessed height, weight, and dietary intake, physical activity, and sleep (lifestyle) habits.ResultsThe BMI of shift workers was significantly higher than that of day workers. Shift workers consumed significantly higher amounts of sugar-sweetened beverages and slept for significantly shorter durations on nights between days on the day shift compared with day workersfactors which were also independently associated with higher BMI. In addition, multivariable linear regression coefficients for BMI showed a significant correlation with rotating shift work (=0.051), after controlling for lifestyle habits.ConclusionsHigher consumption of sugar-sweetened beverages and shorter sleep duration were associated with rotating shift work and higher BMI. This should be taken into consideration in preventing obesity in real-life shift work situations. Other shift work-related factors, such as abnormal timing of meals and/or sleep, should also be identified.

Background: Misalignment of circadian systems is detrimental to human health. However, only a few studies have examined the influence of late meals on the human circadian system. The purpose of this study was to investigate whether delayed meals affect circadian rhythm as assessed by heart rate variability (HRV).Methods: Seven healthy men (aged 22.4 +/- 0.4 years) participated in this study, which involved delaying mealtimes by 5 h for two weeks. Prior to this study, the regular mealtimes of participants were at 08:00, 13:00, and 18:00 (Baseline). During the intervention, each meal was provided at 13:00, 18:00 and 23:00 (Late mealtimes). Circadian variation was assessed by HRV based on R-R intervals calculated from a pulse at the rising phase of each spike in the QRS complex in a 24-h electrocardiograph record. The ratio of low frequency (LF) to high frequency (HF) power (LF/HF) and the ratio of HF power to total power (%HF) were calculated using spectral analysis. The phase and amplitude of HRV variables in a 24-h period were mathematically obtained with double cosinor analysis.Results: The acrophase and amplitude for LF power, HF power and %HF in a 24-h period were not significantly different between Baseline and Late mealtimes. On the other hand, the acrophase significantly differed between Baseline and Late mealtimes for heart rate (95%Cl, 1.1-3.8 h), standard deviation of R-R intervals (95%0, 2.5-4.4 h) and LF/HF (95%0, 1.1-2.3 h).Conclusions: Our findings suggest that delayed mealtimes shift the phase of circadian rhythm of the autonomic nervous system. (C) 2013 Elsevier Inc. All rights reserved.

The purpose of this study was to investigate whether scheduling meals earlier in the day affects the circadian phase of the cardiac autonomic nervous system as assessed by heart rate variability (HRV) and serum lipid levels.

【目的】大学女子新体操選手を対象にオフ期に実施する栄養教育が減量期のたんぱく質摂取量の低下を防ぎ，貧血発現が予防できる可能性を検討する。【方法】2009年6月（減量期前）から2010年8月（減量期後）まで協力の得られた14名を対象とした。2010年2月から4月上旬（オフ期）に貧血予防のためのたんぱく質摂取の重要性を講話し，食材購入や調理実習，献立作成演習などを体験させた。調査項目は体重，体脂肪率，貧血指標，エネルギー，たんぱく質，たんぱく質を多く含む食品群の摂取量とし，2009年度と2010年度の減量期前と減量期後に計4回調査した。2009年度の各値は教育実施前の対照値とした。【結果】減量期前の身体特性，末梢血液一般検査，食物摂取状況は体重，BMI，除脂肪体重，RBCを除き2009年度と2010年度との間に有意な差はみられなかった。2009年度のたんぱく質エネルギー比率，豆類，卵類摂取量は，減量期前に比べ減量期後が有意に減少したが，2010年度は体脂肪率が有意に減少し，卵類摂取量は増加した。減量期の変化量は，教育を行った2010年度が2009年度に比べて体脂肪率は有意な低値を示し，たんぱく質摂取量，たんぱく質エネルギー比率，豆類，卵類摂取量は有意な高値を示した。しかし，Htを除く貧血指標には有意な変化を及ぼすことはなかった。【結論】オフ期の栄養教育はたんぱく質摂取量の低下を抑制するものの，Htを除く貧血指標には影響を及ぼさないことが示唆された。