Energy Intake from Healthy Foods Is Associated with Motor Fitness in Addition to Physical Activity: A Cross-Sectional Study of First-Grade Schoolchildren in Japan.

Childhood motor fitness is important for the physical and mental health of children and the prevention of future lifestyle diseases. This study aimed to investigate how energy intake from healthy foods and physical activity are associated with motor fitness among first-grade children. First-grade children (aged 6-7 years) attending three public elementary schools in Tokyo, Japan (n = 884), participated in this cross-sectional study. Self-administered questionnaires were distributed, which focused on lifestyle habits and required completion of a 1-day dietary record of meals that children ate at home. School lunch consumption was also assessed. Motor fitness was assessed by the New Physical Fitness Test (NPFT). Multiple regression analysis was used to investigate the association of the amount of energy from healthy foods and physical activity with NPFT scores. NPFT scores were positively correlated with involvement in after school exercise classes, playing outside (in boys only), and total energy intake. Energy intake from healthy foods showed a positively associated with NPFT scores (boys, ß = 0.120, p = 0.011; girls, ß = 0.140, p = 0.004), while energy intake from unhealthy foods did not. Energy intake from healthy foods was associated with motor fitness in children in addition to physical activity.

Breakfast before resistance exercise lessens urinary markers of muscle protein breakdown in young men: A crossover trial.

OBJECTIVES: Skipping breakfast prolongs the fasting state initiated after the last meal consumed the previous day and can have negative effects on muscle protein balance. The aim of this crossover trial was to examine the effects of skipping breakfast before a single bout of resistance exercise (RE) on muscle protein breakdown (MPB), as assessed using the urinary 3-methylhistidine/creatinine ratio (3-MH/Cr). METHODS: Thirteen healthy young men, who habitually consumed breakfast (21.8 ± 1.1 y of age), were assigned to eating breakfast (EB) and skipping breakfast (SB) conditions. Participants consumed meat-free diets throughout the 5-d experiment. On day 5, individuals in the EB group consumed breakfast (497 kcal) 2.5 h before RE (75% repetition maximum), whereas those in the SB group consumed the same meal after dinner. RESULTS: In the two-way analysis of variance, significant interactions were observed with blood insulin and free fatty acid levels, and the 3-MH/Cr ratio (P < 0.05). We confirmed a significantly greater decrease in the insulin level pre-RE (P < 0.001; d = 3.281), and increases in the free fatty acid level pre-RE (P < 0.001; d = 1.437) and post-RE (P = 0.013; d = 0.811) and the 3-MH/Cr ratio 6 (P < 0.001; d = 0.878) and 8 h (P < 0.001; d = 0.634) post-RE in the SB condition than in the EB condition. CONCLUSION: Eating breakfast before RE can be beneficial for MPB suppression. The importance of breakfast consumption in terms of positive muscle protein balance is emphasized on sports fields.

Time-of-Day of Energy Intake Is Associated with Body Fat Percentage in Japanese Female University Rhythmic Gymnasts and Non-Athlete Students.

This study investigated whether body fat percentage (BF%) in Japanese female university rhythmic gymnasts (RG) and non-athletes (control) was associated with the time-of-day of energy intake. A total of 57 females (RG group, n=34; control group, n=23) completed 24-h dietary recall surveys on 3 non-consecutive days. BF% was measured using a bioelectrical impedance analyzer after overnight fasting. Energy intake was stratified by time-of-day: morning (3:00 to 11:00), midday (11:00 to 17:00), evening (17:00 to 21:00), and nighttime (21:00 to 3:00). There was no significant difference between the groups in total energy intake, body weight, or body mass index. The RG group had significantly higher energy expenditure, a larger negative energy balance and lower BF% than the control group. The energy intake ratios (ER%) in the evening and at nighttime in the RG group were significantly lower and higher than in the control group, respectively. Total energy intake and energy balance did not show any significant association with BF% in either group. Multivariate linear regression with substitution model indicated that a substitution of ER% in the morning for ER% at nighttime was negatively associated with BF% after adjusting for confounding factors (ß=-0.240; 95% confidence interval (CI): -0.455, -0.025) in the control group. In the RG group, a substitution of ER% in the evening for ER% at nighttime was negatively associated with BF% (ß=-0.117; 95%CI: -0.214, -0.019). These results suggest that the timing of energy intake throughout the day is associated with BF% in Japanese university RG and non-athlete female students.

Validity and Reproducibility of a Self-Administered Food Frequency Questionnaire for the Assessment of Sugar Intake in Middle-Aged Japanese Adults.

We evaluated the validity and reproducibility of estimated sugar intakes using a food frequency questionnaire (FFQ) among middle-aged Japanese adults in the Japan Public Health Centre-Based Prospective (JPHC) study. In subsamples of the JPHC study (Cohorts I and II in multiple areas), we computed Spearman's correlations of FFQ results with urine sugar concentrations and dietary records (DR) for validity; we evaluated correlations between two FFQs for reproducibility. During 1994⁻1998, participants (Cohort I: n = 27 [men], n = 45 [women]) provided two (spring and fall) 24-h urine samples and completed 7-consecutive-day DR per season (I: n = 99, n = 113; II: n = 168, n = 171) and two FFQs (147 food items) at yearly intervals (I: n = 101, n = 108; II: n = 143, n = 146). Sugar intakes from FFQ were correlated with urinary sugar (de-attenuated correlations: 0.40; 95%CI: 0.19, 0.58). After adjustment for sociodemographic and lifestyle variables, correlations between FFQ and DR for men and women were 0.57 (0.42, 0.69) and 0.41 (0.24, 0.55) (I) and 0.56 (0.44, 0.65) and 0.34 (0.20, 0.47) (II), respectively. Correlations between FFQs for men and women were 0.63 (0.49, 0.73) and 0.55 (0.41, 0.67) (I) and 0.66 (0.55, 0.74) and 0.63 (0.52, 0.72) (II). In conclusion, our study showed moderate FFQ validity and reproducibility for sugar intake evaluation.

Higher energy intake at dinner decreases parasympathetic activity during nighttime sleep in menstruating women: A randomized controlled trial.

BACKGROUND: Previous studies have found more frequent increases in dietary intake and nonrestorative nocturnal sleep during the luteal phase than in the follicular phase, but few studies have investigated how increased energy intake at dinner influences sleep by considering the correlation between female hormone and cardiac autonomic nervous system (ANS) activity. This study examined the effects of energy intake at dinner on ANS activity during nighttime sleep in order to evaluate restorative sleep in healthy women. We also examined whether ANS activity is associated with female hormone dynamics. METHODS: Twenty-four healthy collegiate women participated in this randomized crossover trial. Each was assigned to receive a High Energy Dinner (HED) or Low Energy Dinner (LED) treatment. Energy ratios of each test meal (breakfast, lunch, and dinner) to total energy intake were 1:1:2 and 1:2:1 for HED and LED treatments, respectively. Each participant wore an ECG recorder before dinner and removed it upon waking the next morning. Power spectral analysis of heart rate variability was used to calculate low frequency (LF), high frequency (HF), and total spectral power (TP). Cardiac sympathetic (SNS) and parasympathetic (PNS) nervous system activity were evaluated as LF/HF and HF/TP, respectively. RESULTS: Mean HF/TP for the entire sleeping period was lower with HED treatment compared to LED treatment (41.7 ±â€¯11.4 vs. 45.0 ±â€¯12.13, P = .034). Intergroup comparisons of the initial 3-h sleeping period revealed that LF/HF (0.87 ±â€¯0.82 vs. 0.66 ±â€¯0.82, P = .013) and HF/TP (45.6 ±â€¯13.9 vs. 51.5 ±â€¯11.8, P = .002) were higher and lower, respectively, with HED treatment compared to LED treatment. Progesterone levels were positively correlated with LF/HF with LED treatment, and negatively correlated with HF/TP with both HED and LED treatments. CONCLUSION: Higher energy intake at dinner increases and decreases SNS and PNS activities, respectively, resulting in nonrestorative nocturnal sleep. In addition, a negative correlation was observed between progesterone and PNS activity, highlighting the difficulty of increasing PNS activity during sleep in the luteal phase compared to the follicular phase.

Association of habitual dietary intake with morningness-eveningness and rotating shift work in Japanese female nurses.

Rotating shift workers are associated with imbalanced dietary intakes. Rotating shift workers and dietary intakes in adults who do not engage in night work have also been shown to be associated with chronotype. However, no studies have examined associations between morningness-eveningness (i.e., the degree to which people prefer to be active in the morning or the evening), rotating shift work and dietary intakes. Therefore, our first purpose was to elucidate the association between morningness-eveningness and habitual food group intakes in rotating shift workers. The second purpose was to elucidate the association of morningness-eveningness and rotating shift work with food group intakes, considering habitual sleep durations. Japanese nurses (1095 day workers and 1464 rotating shift workers) were studied using a self-administered questionnaire. The questionnaire covered habitual dietary intakes, morningness-eveningness and demographic characteristics of the participants. A Japanese version of the Morningness-Eveningness Questionnaire (MEQ) was used to measure self-rated morningness-eveningness. Dietary intakes over the previous 1 month were evaluated using a semi-quantitative food frequency questionnaire. Intakes of pulses, green/yellow vegetables, white vegetables, fruits, algae, eggs, confectioneries/savory snacks and sugar-sweetened beverages were significantly (p < 0.05) associated with the MEQ score in rotating shift workers. Among these food groups, intakes of green/yellow vegetables, white vegetables, fruits and algae were significantly (p < 0.05) lower in rotating shift workers than in day workers, and intakes of confectioneries/savory snacks and sugar-sweetened beverages were significantly (p < 0.05) higher in rotating shift workers than in day workers. Intakes of these food groups were also significantly (p < 0.05) associated with the MEQ score in day workers. In addition, the MEQ score was significantly (p < 0.05) lower in rotating shift workers than in day workers, indicating greater eveningness among rotating shift workers. Multivariate linear regression revealed that the MEQ scores were significantly (p < 0.05) associated with intakes of these food groups, while rotating shift work was associated only with confectioneries/savory snacks. These results suggest that morningness-eveningness is associated with unbalanced dietary intakes in rotating shift workers as well as day workers, which may partially explain associations between rotating shift work and unfavorable dietary intakes. These findings have important implications for the development of novel strategies for preventing poor health caused by imbalanced dietary intakes in rotating shift workers.

The Impact of Menstrual Cycle Phases on Cardiac Autonomic Nervous System Activity: An Observational Study Considering Lifestyle (Diet, Physical Activity, and Sleep) among Female College Students.

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.

Association of eating behaviours with diurnal preference and rotating shift work in Japanese female nurses: a cross-sectional study.

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.

Habitual dietary protein intake affects body iron status in Japanese female college rhythmic gymnasts: a follow-up study.

BACKGROUND: Many rhythmic gymnasts stay lean by reducing their body weight (BW); however, this may result in iron deficiency (ID). Our previous cross-sectional study reported an association between ID incidence and protein intake in gymnasts during the pre-season. The present study aimed to examine the association between dietary protein intake and ID incidence in a 2-year follow-up study. METHODS: Elite Japanese female college rhythmic gymnasts [mean age ± standard deviation (SD): 18.4 ± 0.5 years] were recruited on a voluntary basis every August for 9 years. Anthropometric, dietary intake, and hematological parameters were measured at baseline and 2 years later. A total of 20 participants without ID at baseline were divided into either a lower (L, n = 11) or higher (H, n = 9) protein group based on median protein intake (1.3 g protein/kg BW). RESULTS: Participants consumed 1.08 ± 0.16 and 1.55 ± 0.14 g/kg BW of protein in the L and H groups, respectively. No significant changes in the intake of protein and other nutrients were observed between baseline and 2-year follow-up in both groups. ID was observed in a total of eight (72.8 %) participants in the L group and one (11.2 %) in the H group at follow-up. The incidence of ID was significantly lower in the H group than the L group (Fisher's exact test, odds ratio, 0.043; 95 % CI 0.004-0.552; p = 0.010). CONCLUSIONS: During the pre-season weight loss period, habitually higher protein intake may reduce ID incidence among elite college female rhythmic gymnasts.

Validity of a Semi-Quantitative Food Frequency Questionnaire for Collegiate Athletes.

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.

Relationship Between Dietary Factors and Bodily Iron Status Among Japanese Collegiate Elite Female Rhythmic Gymnasts.

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.

Examining the relationship between vegetable intake of mothers and that of their children: a cross-sectional study of 10- to 12-year-old schoolchildren in Japan.

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.

Association of body mass index with lifestyle and rotating shift work in Japanese female nurses.

OBJECTIVE: Higher 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. METHODS: Japanese 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. RESULTS: The 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 workers-factors which were also independently associated with higher BMI. In addition, multivariable linear regression coefficients for BMI showed a significant correlation with rotating shift work (ß = 0.051), after controlling for lifestyle habits. CONCLUSIONS: Higher 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.

Individual and environmental factors related to stage of change in exercise behavior: a cross-sectional study of female Japanese undergraduate students.

BACKGROUND: The purpose of the current study was to examine the association between the level of exercise behavior and individual and environmental factors related to exercise behavior among female Japanese undergraduate students. METHODS: The participants were 2482 female Japanese undergraduate students. Participants' level of exercise behavior was measured by the stage of change to exercise in the transtheoretical model. Individual and environmental factors related to exercise behavior were assessed using body mass index, self-efficacy, social support, perceived positive and negative aspects of exercise, perceived neighborhood environment, attitude toward physical education lessons in childhood and puberty, and depression. RESULTS: Scores for self-efficacy, social support, positive aspects of exercise, and perceived neighborhood environment were significantly higher among women who were more active compared with those who were inactive. On the other hand, scores for negative aspects of exercise and depression were greater among inactive women compared with those who were insufficiently active and/or active. In addition, past attitude toward exercise in primary school, junior high school, and high school was associated with current level of exercise behavior. CONCLUSIONS: This cross-sectional study confirmed that psychosocial and environmental factors were closely associated with level of exercise behavior among female Japanese undergraduate students.

Effects of feeding schedule changes on the circadian phase of the cardiac autonomic nervous system and serum lipid levels.

PURPOSE: 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. METHODS: Healthy men aged 21.4 ± 0.5 years (n = 14) with a habit of regularly skipping breakfast participated in this parallel trial involving altered feeding schedules. Participants in the early mealtime group (EM group, n = 8) were asked to eat three meals at 8:00, 13:00, and 18:00, and the control group (n = 6) ate at 13:00, 18:00, and 23:00 for 2 weeks. On the measurement day before and after intervention, fasting blood samples and 24-h electrocardiograph recordings were collected. Spectral analysis was used for approximate 10-min HRV segments. Low frequency (LF) power, high frequency (HF) power, and the ratio of HF to total power (%HF) were calculated to assess sympathovagal balance. Acrophases of the circadian rhythm of HRV variables were obtained by nonlinear least squares regression. RESULTS: Triglyceride and total and LDL cholesterol levels were significantly decreased in the EM group when compared with the control group (p = 0.035, 0.008, and 0.004, respectively). Acrophases for HRV variables were advanced in the EM group and their difference between before and after the intervention in LF power (-3.2 ± 1.2 h) and %HF (-1.2 ± 0.5 h) reached significant level, respectively (p < 0.05). CONCLUSIONS: Timing of meals was a key factor in regulating circadian phases of the cardiac autonomic nervous system and lipid metabolism.

Diurnal 24-hour rhythm in ambulatory heart rate variability during the day shift in rotating shift workers.

Circadian variation in cardiac autonomic nervous system activity and behavior during the day shifts of shift workers has not hitherto been clarified. This study examined diurnal 24-h variation in heart rate variability (HRV), sleep-wake cycle, physical activity, and food intake during the day shift in rotating shift workers. The subjects were female nurses and caregivers working at a health care facility (14 day workers and 13 rotating shift workers). Each subject was asked to undergo 24-h electrocardiograph and step count recordings. Coarse graining spectral analysis was used for approximately 10-min segments of HRV (600 beats) to derive the total power (TOT: >0.04 Hz), integrated power in the low-frequency (LF: 0.04-0.15 Hz) and high-frequency (HF: >0.15 Hz) ranges, the ratio of HF power to TOT (HF nu), and the ratio of LF power to HF power (LF/HF). Double cosinor analysis was used to obtain 24-h and 12-h period variations in variables of HRV and physical activity. While no difference was found in the acrophases of either period for step counts or in the 12-h period of HRV variables between the groups, the acrophases of the 24-h period for HRV variables were delayed by 1.3 to 5.5 h in rotating shift workers, and their differences in HF power, HF nu, and LF/HF reached a significant level (p < 0.05). On the days of the experiment, retiring time, waking up time, total time in bed, sleep efficiency, and mealtimes and energy intake for each diet did not differ between the groups. These results suggest that there is a possibility of an abnormal phase angle between circadian variation in cardiac autonomic nervous system activity and the sleep-wake cycle during the day shift in shift workers.

Influence of dietary behavior on the circadian rhythm of the autonomic nervous system as assessed by heart rate variability.

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±0.4years) participated in this study, which involved delaying mealtimes by 5h 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%CI, 1.1-3.8h), standard deviation of R-R intervals (95%CI, 2.5-4.4h) and LF/HF (95%CI, 1.1-2.3h). CONCLUSIONS: Our findings suggest that delayed mealtimes shift the phase of circadian rhythm of the autonomic nervous system.

Effects of egg white protein supplementation on muscle strength and serum free amino acid concentrations.

The aim of this study was to evaluate the effects of egg white protein compared to carbohydrate intake prior to exercise on fat free mass (FFM), one repetition maximum (1RM) muscle strength and blood biochemistry in female athletes. Thirty healthy female collegiate athletes were recruited for this study and matched by sport type, body fat percentage and 1RM leg curl muscle strength. Participants were randomly divided into two groups: protein group (15.0 g egg white protein; 75 kcal) and carbohydrate group (17.5 g maltodextrin, 78 kcal). Supplements were administered daily at the same time in a double-blind manner prior to training during an 8-week period. Measurements were performed before and after the 8-week regimen. The mean dietary energy intake did not change throughout the study period. FFM and 1RM assessments (i.e., leg curl, leg extension, squat, and bench press) increased in both groups. Furthermore, serum urea and serum citrulline levels after the 8-week regimen increased significantly only in the protein group. Our findings indicated that compared to the carbohydrate supplement, the protein supplement was associated with some changes in protein metabolites but not with changes in body composition or muscle strength.

Decreased expression of MHC class II and cathepsin E in dendritic cells might contribute to impaired induction of antigen-specific T cell response in NC/Nga mice.

NC/Nga (NC) mice are an animal model for human atopic dermatitis. We found that induction of antigen (Ag)-specific T cell response is diminished in ovalbumin (OVA)-immunized NC mice. Ability of Ag presentation in NC mouse dendritic cells (DCs) was significantly weaker than that in BALB/c and DBA/2 mouse DCs. Expression levels of MHC class II molecules and cathepsin E in NC mouse DCs were significantly lower that those in BALB/c and DBA/2 mouse DCs. These results indicate that low expression levels of MHC class II and cathepsin E might contribute to the defect in induction of Ag-specific T cells in NC mice.

Relationship of dietary intake and lifestyle factors to health-related quality of life in the community-dwelling elderly.

Quality of life (QOL) encompasses a broad notion of health and is increasingly used to evaluate the effectiveness of health care services. The purpose of this cross-sectional study was to assess health-related quality of life (HR-QOL) in the community-dwelling elderly (mean age, 72.7±0.3 y; female 46.4%, n=179) in Japan and to explore diminished factors. We assessed HR-QOL by the 36-Item Short-Form Health Survey (SF-36), maximum walking speed, step counts, Tokyo Metropolitan Institute of Gerontology (TMIG) index, dietary intake and blood biochemistry. Two summary scores of the SF-36 were calculated (physical component score: PCS, mental component score: MCS). We divided participants into two groups based on the standard values of PCS and MCS classified by age (high and low group), which was further stratified into a high PCS and high MCS (BH) group and a low PCS and low MCS (BL) group. Mean maximum walking speed and daily step counts were 207.7±2.8 cm/s and 7,008±289. Eighty-one percent of the participants had full scores in the TMIG index. Daily intake of energy and protein were 2,081±33 kcal and 74.5±0.9 g. The maximum walking speed, TMIG index, alcohol consumption and chewing ability were significantly higher in the BH group than those in the BL group, but not dietary intake. Stepwise logistic regression analysis indicated that maintaining maximum walking speed might be associated with sustaining HR-QOL in the healthy elderly.