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Little is known about the optimal daily magnesium (Mg) intake for individuals with high levels of physical activity. The aim of this study was to clarify the optimal dietary Mg intake for people with high levels of physical activity in a scoping review. In this review, we searched MEDLINE and Japan Medical Abstracts Society for studies published up to May 31, 2020. We conducted two searches, one for studies using gold standard measurement methods such as the balance method and factorial calculation (Search 1), and the other for studies using estimation from daily food intake (Search 2). We also performed a meta-analysis of studies that compared the Mg intake among physically active people with the Mg intake among controls. After the primary and secondary screening, 31 studies were included in the final review. All of the included studies examined professional or recreational athletes. We found no studies that examined the optimal intake of Mg using gold standard measurement methods. The Mg intake among physically active individuals was below the recommended dietary allowance in most studies. In five studies that conducted meta-analyses, physically active individuals had significantly higher intakes of Mg than controls, although these levels were still below the recommended dietary allowance. The present review revealed that evidence regarding the optimal daily magnesium intake is currently scarce, and further studies are needed.

This study determined the relationship between intra-individual variability in day-to-day nutrition-related lifestyle behaviors (meal timing, eating window, food intake, movement behaviors, sleep conditions, and body weight) and glycemic outcomes under free-living conditions in adults without type 2 diabetes.We analyzed 104 adults without type 2 diabetes. During the 7-day measurement period, dietary intake, movement behaviors, sleep conditions, and glucose outcomes were assessed. Daily food intake was assessed using a mobile-based health application. Movement behaviors and sleep conditions were assessed using a tri-axial accelerometer. Meal timing was assessed from the participant's daily life record. Blood glucose levels were measured continuously using a glucose monitor. Statistical analyses were conducted using a linear mixed-effects model, with mealtime, food intake, body weight, movement behaviors, and sleep conditions as fixed effects and participants as a random effect.Dinner time and eating window were positively significantly correlated with mean (dinner time, p = 0.003; eating window, p = 0.001), standard deviation (SD; both at p 0.001), and maximum (both at p 0.001) blood glucose levels. Breakfast time was negatively associated with glucose outcomes (p 0.01). Sedentary time was positively significantly associated with blood glucose SD (p = 0.040). Total sleep time was negatively significantly correlated with SD (p = 0.035) and maximum (p = 0.032) blood glucose levels. Total daily energy intake (p = 0.001), carbohydrate intake (p 0.001), and body weight (p 0.05) were positively associated with mean blood glucose levels.Intra-individual variations in nutrition-related lifestyle behaviors, especially morning and evening body weight, and food intake, were associated with mean blood glucose levels, and a long sedentary time and total sleep time were associated with glucose variability. Earlier dinner times and shorter eating windows per day resulted in better glucose control.

Previous cross-sectional studies indicated that low relative skeletal muscle mass against body weight (appendicular lean mass divided by body weight, ALM/Wt or divided by body mass index, ALM/BMI) was negatively associated with metabolic syndrome (MetS). The aim of this longitudinal study was to investigate the impact of low relative skeletal muscle mass and leg muscle power on the development of MetS in Japanese women in a 7-y prospective study. Subjects were 346 Japanese women aged 26 to 85 years. The reference values for Class I sarcopenia were defined as values one SD below the sex-specific means of the young group. The longitudinal relation between muscle mass or leg power and development of MetS was examined using Kaplan-Meier curves and Cox regression models (average follow-up duration 7 years, range 1 to 10 years). During follow-up, 24 of subjects developed MetS. Both indices of ALM/Wt or ALM/BMI, the incidence of MetS was higher in Class I sarcopenia group than normal muscle mass group even after controlling variables (adjusted hazard ratio [AHR] = 3.22 [95%CI; 1.25-8.27] for ALM/Wt and 3.19 [95%CI; 1.31-7.74] for ALM/BMI). In contrast, for the leg power per body weight, the incidence of MetS was not significantly different between low leg power and normal leg power groups (AHR = 1.23 [95%CI; 0.50-3.04]). Current longitudinal study indicated that low relative skeletal muscle mass but not low leg power was independent risk factors for the development of MetS in Japanese women.

Previous cross-sectional studies have indicated that low relative appendicular lean mass (ALM) against body weight (divided by body weight, ALM/Wt, or divided by body mass index, ALM/BMI) was negatively associated with metabolic syndrome (MetS). Conversely, previous cross-sectional studies have indicated that the absolute ALM or ALM divided by squared height (ALM/Ht2) were positively associated with MetS. The aim of this longitudinal study was to investigate the association between low absolute or relative skeletal muscle mass, leg muscle power, or percent body fat and the development of MetS in Japanese women in a 7-y prospective study. The study participants included 346 Japanese women aged 26 to 85 years. The participants were divided into low and high groups based on the median values of ALM/Wt, ALM/BMI, ALM/Ht2, absolute ALM, or leg power. The longitudinal relationship between ALM indices or leg power and MetS development was examined using Kaplan-Meier curves and Cox regression models (average follow-up duration 7 years, range 1 to 10 years). During follow-up, 24 participants developed MetS. MetS incidence was higher in the low ALM/Wt group than the high ALM/Wt group even after controlling for age, obesity, waist circumference, family history of diabetes, smoking, and physical activity [adjusted hazard ratio = 5.60 (95% CI; 1.04–30.0)]. In contrast, MetS incidence was lower in the low ALM/Ht2 group than the high ALM/Ht2 group [adjusted hazard ratio = 10.6 (95%CI; 1.27–89.1)]. MetS incidence was not significantly different between the low and high ALM/BMI, absolute ALM, and leg power groups. Both ALM/Ht2 and ALM/Wt were not significant predictive variables for MetS development when fat mass or percent body fat was taken into account in the Cox model. At the very least, the results of this study underscore the importance of body composition measurements in that percent body fat, but not ALM, is associated with MetS development.

BACKGROUND Some studies on weight loss promotion using smartphone applications (smartphone app) including mobile applications have shown a weight loss effect, but not an increase in physical activity, and they have not been rigorously examined for longer periods. OBJECTIVE To assess whether the use of a smartphone app will increase physical activity and reduce body weight. METHODS In this parallel randomized clinical trial, participants recruited between April 2018 and June 2019 were randomized in equal proportions to a smartphone app group (n=55) or control group (n=54). The intention-to-treat approach was used to analyze the data from December 2019 through November 2021. Before the intervention, an hour-long lecture on weight loss instruction and increasing physical activity was conducted once for both groups. Participants in both groups were instructed to weigh themselves immediately after waking up at least once daily from the start of the intervention. Monthly e-mails were sent advising the participants on how to lose weight and increase physical activity in order to maintain or increase motivation in both groups. Participants in the smartphone app group were instructed to launch the app at least once a day to check their step count and rank. The primary outcome was daily accelerometer-measured physical activity (step count) and secondary outcomes was body weight. RESULTS The 109 participants had a mean (standard deviation) age of 47 (8) years. At baseline, the mean (standard deviation) daily total steps were 7259 (3256) for the smartphone app and 8243 (2815) for control groups, respectively. After the 32-week intervention period, the step count per wear time was significantly higher in the smartphone app group than in the control group [average difference (95%CI): 65 (30 to 101) vs. -9 (-56 to 39), p=0.042]. The weight loss was -2.2 kg (-3.1%) in the smartphone app group and -2.2 kg (-3.1%) in the control group, with no significant difference between the groups. During the intervention period, the step count per wear time on Saturdays [615 (545 to 684) vs. 554 (483 to 624), p=0.006] and Sundays [623 (553 to 694) vs. 556 (485 to 627), p=0.004] was significantly higher in the smartphone app group than in the control group. CONCLUSIONS In this trial, the smartphone app group showed increased physical activity, especially on weekends. However, this increased physical activity did not lead to weight loss. CLINICALTRIAL UMIN000033397 https://upload.umin.ac.jp/cgi-open-bin/ctr/ctr.cgi?function=brows&action=brows&recptno=R000037956&type=summary&language=J

Objective:Self-reported energy intake (EI) estimation may incur systematic errors that could be attenuated through biomarker calibration. We aimed to confirm whether calibrated EI was comparable to total energy expenditure (TEE) measured using the doubly labelled water (DLW) technique.Design:Cross-sectional study.Setting:General older population from the Kyoto–Kameoka Study, Japan.Participants:This study included sub- and main cohorts of 72 and 8058 participants aged≥ 65 years, respectively. EI was evaluated using a validated FFQ, and calibrated EI was obtained using a previously developed equation based on the DLW method. TEE was considered representative of true EI and also measured using the DLW method. We used a Wilcoxon signed-rank test and correlation analysis to compare the uncalibrated and calibrated EI with TEE.Results:In the sub-cohort, the median TEE, uncalibrated EI and calibrated EI were 8559 kJ, 7088 kJ and 9269 kJ, respectively. The uncalibrated EI was significantly lower than the TEE (median difference = –1847 kJ; interquartile range (IQR): –2785 to –1096), although the calibrated EI was not (median difference = 463 kJ; IQR: –330 to 1541). The uncalibrated (r = 0·275) and calibrated EI (r = 0·517) significantly correlated with TEE. The reproducibility was higher for calibrated EI (interclass correlation coefficient (ICC) = 0·982) than for uncalibrated EI (ICC = 0·637). Similar findings were observed when stratifying the sample by sex. For medians, uncalibrated EI was lower (about 17 %) than calibrated EI in the main cohort.Conclusions:Biomarker calibration may improve the accuracy of self-reported dietary intake estimation.

Background Some studies on weight loss promotion using smartphone apps have shown a weight loss effect but not an increase in physical activity. However, the long-term effects of smartphone apps on weight loss and increasing physical activity have not been rigorously examined to date. Objective The aim of this study was to assess whether the use of a smartphone app will increase physical activity and reduce body weight. Methods In this parallel randomized clinical trial, participants recruited between April 2018 and June 2019 were randomized in equal proportions to a smartphone app group (n=55) or a control group (n=54). The intention-to-treat approach was used to analyze the data from December 2019 through November 2021. Before the intervention, an hour-long lecture on weight loss instruction and increasing physical activity was conducted once for both groups. Participants in both groups were instructed to weigh themselves immediately after waking up at least once daily from the start of the intervention. Monthly emails were sent advising the participants in both groups on how to lose weight and increase physical activity in order to maintain or increase motivation. Participants in the smartphone app group were instructed to open the app at least once a day to check their step count and rank. The primary outcome was daily accelerometer-measured physical activity (step count) and the secondary outcome was body weight. Since there was a significant difference in the wear time of the accelerometer depending on the intervention period (P Results The mean age of the 109 participants in this study was 47 (SD 8) years. At baseline, the mean daily total steps were 7259 (SD 3256) steps per day for the smartphone app group and 8243 (SD 2815) steps per day for the control group. The difference in the step count per wear time between preintervention and postintervention was significantly different between the app group and the control group (average difference [95% CI], 65 [30 to 101] steps per hour vs –9 [–56 to 39] steps per hour; P=.042). The weight loss was –2.2 kg (SD –3.1%) in the smartphone app group and –2.2 kg (SD –3.1%) in the control group, with no significant difference between the groups. In addition, when divided into weekdays (Monday through Friday) and weekends (Saturday and Sunday), there was a significant interaction between step counts (P=.004) and MVPA (P=.003) during the intervention, with the app group showing higher interaction on weekends than the control group. Conclusions In this trial, the group with the smartphone app intervention showed increased physical activity, especially on weekends. However, this increased physical activity did not lead to increased weight loss. Trial Registration University Hospital Medical Information Network UMIN000033397; https://center6.umin.ac.jp/cgi-open-bin/ctr_e/ctr_view.cgi?recptno=R000037956

Breakfast skipping has become an increasing trend in the modern lifestyle and may play a role in obesity and type 2 diabetes. In our previous studies in healthy young individuals, a single incident of breakfast skipping increased the overall 24-h blood glucose and elevated the postprandial glycaemic response after lunch; however, it was difficult to determine whether this response was due to breakfast omission or the extra energy (i.e. lunch plus breakfast contents). The present study aimed to assess the postprandial glycaemic response and to measure their hormone levels when healthy young individuals had identical lunch and dinner, and the 24-h average blood glucose as a secondary outcome. Nine healthy young men (19−24 years) participated in two-meal trials: with breakfast (three-meal condition) or without breakfast (breakfast skipping condition). During the meals, each individual’s blood glucose was continuously monitored. Skipping breakfast resulted in a significantly higher (P < 0·001) glycaemic response after lunch as compared with the glycaemic response after an identical lunch when breakfast was consumed. Despite the difference in the total energy intake, the 24-h average blood glucose was similar between the two-meal conditions (P = 0·179). Plasma NEFA level was significantly higher (P < 0·05) after lunch when breakfast was omitted, and NEFA level positively correlated with the postprandial glycaemic response (r 0·631, P < 0·01). In conclusion, a single incident of breakfast skipping increases postprandial hyperglycaemia, and associated impaired insulin response, after lunch. The present study showed that skipping breakfast influences glucose regulation even in healthy young individuals.

Daily water intake (DWI) is essential for survival in humans; however, accurate assessment of DWI from drinks and beverages (Wdrinks) or food moisture (Wfoods) is difficult as it depends on self-reported intakes that are prone to inaccuracy. Here, we established an objective method to assess DWI components using doubly labeled water (DLW). Deuterium and H218O were orally administered, and the dilution space and elimination rate of 2H and 18O were measured. DWI was calculated from the deuterium turnover corrected for metabolic water production and insensible water absorption from humidity. Wfoods was estimated using dietary record (Wfoods-DR) or calculated from the total energy expenditure assessed by DLW (Wfoods-DLW). The current results underscore Wfoods-DR underestimation using self-reported dietary assessments, which underestimates food intake. This study proposes novel methods for calculating each DWI component using DLW.

Breaking up sedentary periods, particularly with light activity, increases total energy expenditure (EE), and helps provide better glycemic control. However, the effects of activities of various intensities to interrupt prolonged sedentary time are unclear. The purpose of the present study was to examine potential differences in glycemic control and EE from breaking up sedentary time with short exercise bouts of different intensities.Nine overweight/obesity young men underwent whole body indirect calorimetry at 19:00 on day 1 and stayed overnight. After awakening on day 2, they performed short duration jogging every 30 min over 8 h (16-time bouts in total) under 3 different conditions with the same running distance: (1) lactate threshold (LT) for 2 min, (2) 60% LT for 200 s, and (3) onset of blood lactate accumulation (OBLA) for 75 s. The 24-h EE and interstitial glucose concentration (from 8:00 to 19:00 on day 2) was continuously measured throughout the trials. The standard deviation during intervention and indexes of postprandial of the interstitial glucose concentration was significantly lower at LT and OBLA than at 60% LT (p 0.05). The 24-h EE was not significantly different among conditions, but EE at OBLA during intervention was slightly but significantly higher than at 60% LT and LT.Breaking up sedentary time with short-duration jogging at LT and with OBLA intensities may have better glycemic control and increased use of carbohydrate as a fuel, while short-duration a jogging at OBLA intensity may increase EE.UMIN000041361.

Background Meals, particularly carbohydrate intake, determine diurnal blood glucose (BG) excursions. However, the effect of meals with variable carbohydrate content on diurnal BG excursions remains poorly understood, despite routine consumption of meals that vary daily. Objective The aim of this study was to verify our hypothesis that glycemic response is elevated when a meal with a higher carbohydrate content follows a meal with a lower carbohydrate content. Design This was a secondary analysis of a study whose primary endpoint was energy metabolism (e.g., energy expenditure and substrate oxidation). This crossover study was designed to test BG responses to 3 types of meals with different macronutrient contents [regular meals (R), meals with a high-carbohydrate breakfast (CB), and meals with a high-fat breakfast (FB)] using a continuous glucose monitoring system. The R test included 3 meals/d with the same macronutrient composition; the CB test, a high-carbohydrate meal at breakfast, a high-fat meal at lunch, and a high-carbohydrate meal at dinner; and the FB test, a high-fat meal at breakfast, a high-carbohydrate meal at lunch, and a high-carbohydrate meal at dinner. Each test had similar daily macronutrient compositions, except CB and FB had larger variations in carbohydrate content than R. Fourteen healthy young men were tested in random order and underwent whole-body indirect calorimetry. Results Daily peak BG concentrations were higher for the CB (mean ± SD: 143.9 ± 25.3 mg/dL) and FB (140.2 ± 24.8 mg/dL) conditions than for the R condition (127.5 ± 15.7 mg/dL). Postprandial BG peaks after a high-carbohydrate meal were ∼20 mg/dL higher when a previous meal was relatively high-fat than when not high-fat (P < 0.05 for all). A multiple regression analysis indicated that the postprandial glycemic response was negatively associated with the preprandial respiratory quotient. Conclusions Our findings indicate that switching from high-fat to high-carbohydrate meals contributes to larger postprandial BG excursions, along with alterations in prioritization of carbohydrate utilization. This study was registered at the UMIN Clinical Trials Registry as UMIN000028895.

Genetic polymorphisms and sex differences are suggested to affect muscle fiber composition; however, no study has investigated the effects of genetic polymorphisms on muscle fiber composition with respect to sex differences. Therefore, the present study examined the effects of genetic polymorphisms on muscle fiber composition with respect to sex differences in the Japanese population. The present study included 211 healthy Japanese individuals (102 men and 109 women). Muscle biopsies were obtained from the vastus lateralis to determine the proportion of myosin heavy chain (MHC) isoforms (MHC-I, MHC-IIa, and MHC-IIx). Moreover, we analyzed polymorphisms in α-actinin-3 gene ( ACTN3; rs1815739 ), angiotensin-converting enzyme gene ( ACE; rs4341 ), hypoxia-inducible factor 1 α gene ( rs11549465 ), vascular endothelial growth factor receptor 2 gene ( rs1870377 ), and angiotensin II receptor, type 2 gene ( rs11091046 ), by TaqMan single-nucleotide polymorphism genotyping assays. The proportion of MHC-I was 9.8% lower in men than in women, whereas the proportion of MHC-IIa and MHC-IIx was higher in men than in women (5.0 and 4.6%, respectively). Men with the ACTN3 RR + RX genotype had a 4.8% higher proportion of MHC-IIx than those with the ACTN3 XX genotype. Moreover, men with the ACE ID + DD genotype had a 4.7% higher proportion of MHC-I than those with the ACE II genotype. Furthermore, a combined genotype of ACTN3 R577X and ACE insertion/deletion (I/D) was significantly correlated with the proportion of MHC-I ( r = −0.23) and MHC-IIx ( r = 0.27) in men. In contrast, no significant correlation was observed between the examined polymorphisms and muscle fiber composition in women. These results suggest that the ACTN3 R577X and ACE I/D polymorphisms independently affect the proportion of human skeletal muscle fibers MHC-I and MHC-IIx in men but not in women.NEW & NOTEWORTHY In men, the RR + RX genotype of the α-actinin-3 gene ( ACTN3) R577X polymorphism was associated with a higher proportion of myosin heavy chain (MHC)-IIx. The ID + DD genotype of the angiotensin-converting enzyme gene ( ACE) insertion/deletion (I/D) polymorphism, in contrast to a previous finding, was associated with a higher proportion of MHC-I in men. In addition, the combined genotype of these polymorphisms was correlated with the proportion of MHC-I and MHC-IIx in men. Thus ACTN3 R577X and ACE I/D polymorphisms influence the muscle fiber composition in Japanese men.

Many epidemiological studies indicate a positive relationship between skipping breakfast (SB) and obesity. However, it is unclear whether SB affects energy intake and physical activity during the day. The objective of the present study was to evaluate the acute effects of SB on energy intake and physical activity under free-living conditions. The present study used a randomized, crossover trial design comparing eating breakfast (EB) and SB days. Twenty lean, healthy women 21-25years old who were habitual breakfast eaters (≥5daysperweek) took part in this study. On EB days, participants were provided a standard breakfast (542kcal). The meals and physical activity after breakfast were under free-living conditions. The meals consisted of foods available at supermarkets, restaurants, and convenience stores. Dietary intake was evaluated by adding values from food labels. Physical activity was assessed using a tri-axial accelerometer. Energy intake at lunch was significantly increased after SB compared with EB (+131±188kcal; p=0.0057). Total energy intake per day was significantly lower after SB compared with EB (-262±428kcal, p=0.013). Physical activity energy expenditure was slightly lower after SB compared with EB (-41±75kcal in the morning, p=0.024; -56±129kcalperday, p=0.064). Step counts and time spent physically active over the whole day were not significantly different between conditions. Skipping breakfast reduced energy intake during the day and morning physical activity in healthy women who were habitual breakfast eaters. The decreased energy expenditure related to physical activity after SB did not exceed the decreased energy intake.

Background: In Japan, the incidence of kidney stones has increased markedly in recent decades. Major causes of kidney stones remain unclear, and limited data are available on the relationship between overweight/obesity and the incidence of kidney stones. We therefore evaluated body mass index (BMI) and the incidence of kidney stones in Japanese men. Methods: Of the workers at a gas company, 5984 males aged 20–40 years underwent a medical examination in 1985 (baseline). This study includes 4074 of the men, who were free of kidney stones at baseline and underwent a second medical examination performed between April 2004 and March 2005. BMI was calculated from measured height and weight in 1985, and men were categorized into tertiles. The development of kidney stones during follow-up was based on self-reports from questionnaires at the second medical examination. Results: The average duration of follow-up was 19 years, with 258 participants developing kidney stones during this period. Using the lowest BMI (1st tertile) group as a reference, the hazard ratios (95% confidence intervals [CIs]) for the 2nd and 3rd BMI tertiles were: 1.26 (95% CI, 0.92–1.73) and 1.44 (95% CI, 1.06–1.96), respectively (P for trend = 0.019). After additionally adjusting for potential confounders, such as age, systolic blood pressure, cardiorespiratory fitness, cigarette smoking, and alcohol consumption, the hazard ratios were 1.28 (95% CI, 0.93–1.76) and 1.41 (95% CI, 1.02–1.97), respectively (P for trend = 0.041). Conclusions: These results suggest that increased BMI is a risk factor for kidney stones in Japanese men.

Yuya Watanabe,1–3 Masahiro Ikenaga,4 Eiichi Yoshimura,5 Yosuke Yamada,2,6 Misaka Kimura2,3 1Faculty of Health and Sports Science, Doshisha University, Kyotanabe, Japan; 2Laboratory of Applied Health Sciences, Kyoto Prefectural University of Medicine, Kyoto, Japan; 3Department of Health and Sports, Faculty of Health and Medical Sciences, Kyoto Gakuen University, Kameoka, Japan; 4Central Research Institute for Physical Activity, Fukuoka University, Fukuoka, Japan; 5Department of Food and Health Sciences, Prefectural University of Kumamoto, Kumamoto, Japan; 6Laboratory of Healthy Longevity Research, National Institute of Health and Nutrition, National Institutes of Biomedical Innovation, Health and Nutrition, Tokyo, Japan Background: Skeletal muscle experiences both quantitative and qualitative changes with aging. Echo intensity (EI) of the skeletal muscle obtained by ultrasonography (US) has been considered to reflect muscle quality. This technique is noninvasive, easily accessible, and is relatively inexpensive than that of other imaging techniques such as computed tomography (CT). Previous studies have reported that EI is related to several physical performances. However, few studies have investigated the validity of EI against other imaging methods in case of imaging of the skeletal muscle. We compared quantitative and qualitative indices evaluated by the US and CT imaging systems to strengthen their validity.Participants and methods: A total of 40 adults participated in this study: 19 young (10 men and 9 women; their mean (±SD) age was 22.7±1.5 years) and 21 older adults (13 men and 8 women; their mean age was 70.6±4.8 years). Both thighs of each participant were evaluated using US and CT imaging systems.Results: With respect to the US indices, the young group had significantly higher muscle thickness (MT) of the front thigh (P

Background Boxers need to consider energy metabolism during rapid weight loss (RWL) followed by rapid weight regain. We examined the effects of RWL and a 3-h acute weight recovery on energy expenditure, carbohydrate oxidation, and fat oxidation in boxing athletes. Methods The analysis was based on the data of seven healthy young male athletes who underwent rapid weight loss followed by acute weight recovery. Energy expenditure was evaluated at three time points: one week prior to the acute weight loss (baseline); after the 1-week weight loss period; after a 3-h acute weight recovery period. This three-component model was used to estimate body composition. Sleeping metabolic rate and diet-induced thermogenesis (DIT) were measured in an indirect calorimetry room over a 17-h period. After an overnight fast, a prescribed meal was provided and the DIT was measured over a 3-h period. This was followed by a three-step treadmill running protocol. Results Weight loss produced a significant decrease in fat mass, fat free mass, and body mass, with recovery of body mass within 3 h (1.7±0.3 kg). Postprandial carbohydrate oxidation was significantly lower during the recovery period than at baseline, while fat oxidation was higher, although there was no change in the DIT. Conclusions RWL, followed by a short-term of acute weight recovery, produces an increase in fat oxidation and a decrease in carbohydrate oxidation, with the increase in fat oxidation being maintained through an overnight sleep period, as well as in the postprandial and exercise periods.

Background Dietary protein intake is inversely associated with physical frailty risk. However, it is unknown whether an association exists between dietary protein intake and comprehensive frailty. Objective To evaluate the association between protein intake and comprehensive frailty in older Japanese adults. Design, setting and participants This cross-sectional study included 5638 Japanese participants (2707 men and 2931 women) aged ≥65 years from Kameoka City, Kyoto, Japan. Measurements Dietary intake was estimated using a validated self-administered food frequency questionnaire. Comprehensive frailty was assessed using a 25-item Kihon Checklist (KCL), which comprised instrumental activities of daily living, mobility disability, malnutrition, oral or eating function, socialization and housebound, cognitive function, and depression domains. A KCL score of 4 to 6 was defined as prefrailty, and ≥7 as frailty. Results In women, but not in men, protein intake showed a lower prevalence for prefrailty (Q1-Q4, 40.2%, 34.3%, 34.3%, and 36.0%). Higher protein intake was associated with lower prevalence of frailty both in men (32.5%, 28.4%, 28.3%, and 27.3%) and women (35.7%, 31.4%, 27.6%, and 28.2%). Moreover, higher dietary protein intake decreased the odds ratio (OR) for frailty after adjustment for potential confounding factors in both men (OR for highest vs lowest quartile, 0.62; 95% CI, 0.43-0.89; P for trend = 0.016) and women (OR 0.64; 95% CI, 0.45-0.91; P for trend = 0.017). Conclusions/implications The higher dietary protein intake may be inversely associated with the prevalence of comprehensive frailty in Japanese men and women. Future studies are needed to examine associations of dietary protein intake within KCL domains.

It is well known that imbalances in the dietary electrolytes are associated with a significantly higher incidence of cardiovascular disease (CVD). On the other hand, a prolonged heart rate corrected-QT (QTc) interval is associated with an increased risk of cardiac autonomic nervous system dysfunction, the incidence of CVD and sudden cardiac death. This study was designed to clarify the association between the nutritional status and the QTc interval in elderly subjects. The subjects included 119 elderly subjects (46 males and 73 females, age; 72.9±4.8 y) without a history of CVD, who were taking cardioactive drugs. Resting 12-lead electrocardiography was performed, while the QTc interval was calculated according to Bazett's formula. The nutritional status was assessed using a brief self-administered diet history questionnaire. The subjects were divided into three categories, which were defined as equally trisected distributions of the body mass index (BMI). The QTc interval was significantly longer in both the low and high BMI groups than in the moderate BMI group in both genders (p

We aimed to investigate whether frequencies of protein-rich food intake were associated with frailty among older Japanese adults. A cross-sectional study was conducted in 2011 among 3843 men and 4331 women in a population-based cohort of Kameoka city, Kyoto Prefecture, Japan. Frailty was assessed by the weighted score based on the 25-item Kihon-Checklist. The frequency of protein-rich food intake was examined as “seafood”, “meat”, “dairy products”, “eggs”, and “soy products”. The outcome of frailty was analyzed with a multiple logistic regression model using the frequency of protein-rich food intake. When compared to the first quartile, it was observed that there was a significant association between the lower adjusted prevalence ratio (PR) for frailty and the frequency of seafood intake in the fourth quartile among men (PR 0.64, 95% confidence interval (CI), 0.42, 0.99) and from the second quartile to the third quartile among women (PR 0.61, 95% CI, 0.43, 0.85; PR 0.64, 95% CI, 0.46, 0.91). The frequency of dairy products intake in the third quartile among women was significantly associated with a lower PR for frailty (p-value = 0.013). Our findings suggest that the consumption of seafood and dairy products may help older adults in maintaining their independence.

Our objective was to clarify the effect of sleep curtailment on energy intake (EI) and physical activity under free-living conditions. Participants were 16 healthy women aged 21-22years. A randomized crossover trial design was used to compare a short sleep condition (SS): 4h/night (2:00-6:00) and a control sleep condition (CS): 7h/night (23:00-6:00). Each condition comprised 3 consecutive nights. Sleep duration was assessed using a wristwatch-type accelerometer at home. All living activities except sleeping were free-living. Physical activity was assessed using a tri-axial accelerometer, and was categorized by intensity level (sedentary; sedentary to light; moderate to vigorous). Participants were asked to purchase and consume meals with visible nutrient information. EI was evaluated by adding values from these food labels. Mean sleep duration in the two conditions was significantly different (4.3±0.3 vs. 7.1±0.4h, p0.01). For the shared wakefulness period in the two conditions (6:00-23:00), step counts and physical activity were not significantly different. Sedentary time (878±61 vs. 727±40min, p0.01), and sedentary to light-intensity activity time (1122±18 vs. 932±63min, p0.01) were significantly increased in SS (waking time, 06:00-02:00) compared with CS (waking time, 06:00-23:00). However, these significant effects were clearly attenuated after adjustment for awake time (p0.05). Total EI was not significantly different between conditions (8.64±0.82 vs. 8.46±1.28MJ, p0.05), nor were leptin levels (p0.05), but insulin and cortisol levels after SS were significantly higher than after CS (p0.05). In this study, physical activity was increased in the SS condition and attributed to differences in awake time between conditions. However, there were no differences in EI. Further studies to investigate the effect of sleep curtailment on weight gain through stress and insulin resistance are necessary.

Objective The Kyoto-Kameoka Study was launched in 2011–2012 to identify the associations among food intake, nutritional status, physical activity, oral function, quality of life or social capital, the use of long-term care insurance (LTCI) system, and healthy lifespan in community-dwelling older people as a part of the World Health Organization Safe Community program. Design A prospective cohort study, reporting baseline demographics (cross-sectional data). Setting and participants We conducted 2 mailed self-administered questionnaire surveys; one is a complete population survey with a comprehensive survey of needs in the sphere of daily life (NSDL) that included 2 different frailty indexes, the Kihon Checklist (KCL) and the Fried phenotype, socioeconomic status, general and psychological health, and social relationships; followed by the more detailed Health and Nutrition Survey. A slightly modified NSDL survey was conducted again in 2013. Survival time, LTCI certification, and medical and long-term care costs after the baseline survey will be followed. Results Of 18,231 NSDL questionnaires distributed, 13,294 people responded (response rate: 72.92%; mean age 73.7 ± 6.4 and 75.1 ± 7.2 years for men and women, respectively; 12,054 people without and 1240 with LTCI certification). In people without LTCI, the proportion of robust, prefrail, and frail were 30.3%, 59.8%, and 9.9% in men and 25.3%, 64.7%, and 10.0% in women, according to the Fried index. The proportion of frail people as defined by KCL ≥7 was 30.8% in men and 33.3% in women. Conclusions The study is the first to document frailty prevalence using both Fried and KCL measures with a complete city population survey among older Japanese in the community as a part of World Health Organization Safe Community program. The study is expected to provide valuable evidence of the effects of lifestyle habits on long-term care prevention and healthy life span.

Salt reduction is one of the most important lifestyle modifications for the prevention of hypertension. The health promotion law regulates the labeling of the nutrient content of food in Japan and, the level of sodium, not salt (sodium chloride), has to be printed on the labels of manufactured foods. In order to control their salt intake, consumers need to apply a conversion factor to the sodium levels listed on the labels to obtain the salt equivalent. However, it is not known whether people have the knowledge appropriate for making the conversion. We carried out a questionnaire survey at the 7th National Shokuiku (food education) Conference in 2012, asking subjects to determine the salt equivalent of 1000 mg of sodium on food labels. We also asked about the target values of salt reduction in grams in the Dietary Reference Intakes for Japanese 2010 (DRI2010) and the Guidelines for Management of Hypertension 2009 by the Japanese Society of Hypertension (JSH2009). We analyzed the data from 683 respondents (169 men and 514 women); only 13.3% of respondents gave a correct answer for the salt equivalent of 1000 mg of sodium (2.50-2.60 g), whereas 61.8 and 40.4% of respondents chose the correct target values for salt reduction according to DRI2010 and JSH2009, respectively. In conclusion, few people could convert sodium content to salt, which suggested difficulty in using food labels to control their salt intake. Salt content in grams, not sodium content, should be labeled on food packages for effective salt reduction and prevention of hypertension.

Background During the year after the Great East Japan Earthquake on March 11, 2011, the health conditions and lifestyles of survivors were extensively surveyed. We examined the relationship between living conditions and dietary pattern among survivors. Methods A total of 10 466 survivors aged 18 years or older (25% of the population of that age in the area) participated in a survey of Iwate Prefecture. The average frequency of daily consumption of 8 food groups was determined by questionnaire. After excluding staple foods, which were consumed 3 times a day by 85% of participants, factor analysis was performed on 7 food groups among 9789 people (3795 men, 5994 women). Results Factor analysis identified 2 dietary patterns—prudent and meat. The prudent dietary pattern is characterized by high intakes of fish and shellfish, soybean products, vegetables, fruit, and dairy products and was more evident among older participants and women. The meat dietary pattern is characterized by high intakes of meat and eggs and was more evident among younger participants and men. Age-adjusted multiple logistic regression analyses showed that male and female current smokers and men and women living in difficult conditions were likely to have a lower prudent dietary pattern score; male current smokers and male daily alcohol drinkers were likely to have a higher meat dietary pattern score. Conclusions During the year after the earthquake, the prudent dietary pattern was associated with better living conditions among survivors, whereas the meat dietary pattern was not.

Background Physical inactivity is a health issue that often occurs after serious disaster. Social factors, which can be disrupted by disaster, are important determinants of physical activity levels in everyday living. This study was designed to confirm the association between social factors and physical activity among elderly survivors of the Great East Japan Earthquake. Methods From September 2011 to February 2012, 4316 males and females aged 65 or older participated in a health survey of Great East Japan Earthquake survivors. Multiple logistic regression analyses were performed with the dichotomous dependent variable of physical activity (high versus low) and working status, social network, and place of residence (one’s own home versus elsewhere) as independent variables. Results Participants who had been displaced from their homes were more likely to have low physical activity (odds ratio [OR], 95 % confidence interval [CI] for men: 1.37, 1.12 to 1.68; for women: 1.30, 1.09 to 1.55). Non-working status was significantly associated with low physical activity (men: 2.03, 1.65 to 2.49; women: 1.94, 1.60 to 2.34). Detriments to the social network were significantly associated with low physical activity (men: 1.71, 1.41 to 2.08; women: 1.79, 1.51 to 2.13). Conclusion Place of residence and social factors were associated with physical activity levels in elderly survivors of the Great East Japan Earthquake. The findings suggest a need for improvement of social factors to encourage increases in physical activity for elderly persons after disaster.

The relationship between minute-by-minute stepping rate under free-living and obesity remains unclear. The purpose of the present investigation was to compare the levels of physical activity (PA) based on the minute-by-minute stepping rate under free-living conditions between normal weight (NW) and overweight and obese (OV) individuals. A total 40 volunteers participated in the present investigation. These participants were divided into NW or OV according to the body mass index (25 kg m(-2) or 25 kg m(-2)). All participants wore a pedometer with a uni-axial accelerometer (Lifecorder-EX 4sec, Kenz, Japan) for 7 days continuously. The Lifecorder determined the number of steps and time spent in PA at100, 100-129, 130 steps min(-1) according to the minute-by-minute stepping rate. The OV group took a significantly fewer number of steps per day in comparison to that in the NW group (p0.05). The average daily stepping rate was significantly lower in the OV group in comparison to that in the NW group (p = 0.01). Furthermore, the OV group spent a significantly shorter time in PA at a 100 steps min(-1) of the stepping rate compared with that in the NW group (p0.05). These results indicate that obese individuals spent significantly shorter time in PA at 100 steps min(-1) of stepping rate in comparison to the NW individuals.

Background Obesity and overweight are increasing in prevalence in developed countries as a result of changing dietary habits and a lack of physical activity. The purpose of the present study was to evaluate the changes in body composition during short-term overfeeding using the three-component model, which is composed of fat mass (FM), total body water (TBW), and fat-free dry solids (FFDS). Methods Ten healthy men completed 3 days of overfeeding during which they consumed 1,500 kcal/day more energy than consumed in their normal diets. Body composition was evaluated at three time points: the day before and after their normal diets and the day after the 3-day overfeeding diet. Results Before and after their normal diets, there were no significant differences in body weight and composition, but after 3 days of overfeeding, body weight, TBW, and FFDS increased 0.7, 0.7, and 0.2 kg, respectively (P

Aim: This study was designed to clarify the difference in the effects of aerobic exercise training and diet on the improvement in the blood lipid profiles in patients with dyslipidemia. Subjects and Methods: The study enrolled 86 patients with dyslipidemia [34 males and 52 females; age, 55 ± 10 years (33 to 71 years); low-density lipoprotein cholesterol (LDL-C), 150 ± 33 mg/dl (74 to 206 mg/dl); high-density lipoprotein cholesterol (HDL-C), 54 ± 12 mg/dl (35 to 87 mg/dl) and triglycerides, 165 ± 65 mg/dl (68 to 318 mg/dl)]. The subjects were randomly allocated to exercise training (n=42) or diet (n=44) group. These patients in the exercise training group were instructed to exercise for more than 300 min per week at the lactate threshold intensity. In the diet group, the target caloric intake was 25 kcal/kg of ideal body weight [height (m)2 × 22] according to the guideline of the Japan Society for the Study of Obesity. Results: After the 12-week intervention, the LDL-C, triglyceride level and body weight decreased in both the exercise training and diet groups (p

This study investigated the longitudinal changes in the physical activity of the Great East Japan Earthquake victims living in temporary housing.Thirty-nine residents (10 men and 29 women) living in temporary housing in Kamaishi City, Iwate Prefecture, participated in a health survey in 2012. Among these residents, 31 who also participated in a health survey in 2011 were included in a longitudinal study of physical activity. The physical activity for two weeks after the health survey was measured using a tri-accelerometer.During the one-year period from 2011 to 2012, the median daily step counts changed from 4,959 (interquartile range: 2,910-6,029) steps/day to 4,618 (interquartile range: 3,007-7,123) steps/day. The step counts increased for 18 people (56%). The amount of moderate to vigorous physical activity changed from 13.3 (interquartile range: 7.7-22.4) METs h/week to 16.1 (interquartile range: 6.3-25.2) METs h/week. An increase in daily step counts occurred for 14 out of 21 subjects who were65 years old (67%) and only 3 out of 10 subjects who were ≥65 years old (30%).It was suggested that physical activity levels increased because the interquartile range of step counts moved in the direction of an increase and the median amount of moderate to vigorous physical activity increased. However, increasing support for physical activity in the future is required because the physical activity levels of the Great East Japan Earthquake victims who were living in temporary housing were still low compared to the national and regional averages.

Weight-classified athletes need an energy intake plan to accomplish target weight reduction. They have to consider body composition and energy metabolism during rapid weight loss followed by rapid weight regain to achieve their energy intake plan. We investigated the effects of rapid weight loss, followed by weight regain, on body composition and energy expenditure. Ten weight-classified athletes were instructed to reduce their body weight by 5% in 7 days. Following the weight loss, they were asked to try to regain all of their lost weight with an ad libitum diet for 12 h. Food intake was recorded during the baseline, weight loss, and regain periods. Fat mass, total body water, and fat-free dry solids were estimated by underwater weighing and stable isotope dilution methods. A three-component model was calculated using Siri's equation. Basal and sleeping metabolic rates were measured by indirect calorimetry. Body composition and energy expenditure were measured before and after weight loss and after weight regain. Body weight, total body water, and fat-free dry solids were decreased after the weight loss period but recovered after weight regain (p0.05). Basal metabolic rate did not change throughout the study. Sleeping metabolic rate decreased significantly during weight loss but recovered after weight regain. Changes in total body water greatly affect body weight during rapid weight loss and regain. In addition, rapid weight loss and regain did not greatly affect the basal metabolic rate in weight-classified athletes.

This study was performed to assess the validity and reproducibility of a questionnaire on physical activity status used for health surveying among victims of the Great East Japan Earthquake.Seventy-four residents (21 men and 53 women) living in temporary housing in Kamaishi City, Iwate Prefecture, participated in this study. The physical activity status questionnaire was composed of 4 questions regarding the frequency of performing domestic and occupational physical activities, the frequency of leaving their residence, walking duration per day, and sedentary time. The physical activity level for 2 weeks was measured using a tri-accelerometer to validate the responses to the questionnaire. Test-retest reproducibility was examined at 2-week intervals.The physical activity levels were 4,521 +/- 2,266 steps/day for men and 4,533 +/- 2,070 steps/day for women. There was a significant difference in step count between those responding differently to the 3 options in the questionnaire regarding average walking duration per day: those who reported walking foror = 60 min, 30-60 min, oror = 30 min had step counts of 5,343 +/- 1,757, 4,760 +/- 1,752, and 3,063 +/- 1,772 steps/day, respectively (P0.05). When the response options for 3 questions (excluding those for sedentary time) were given scores (a higher score for a higher physical activity level), there were significant correlations between question score and step count (r = 0.486, P0.05) and the amount of moderate to vigorous physical activity (r = 0.342, P0.05). The test-retest trial showed a moderate degree of reproducibility, with weighted K coefficients of 0.41-0.65.Three questions on physical activity levels may allow assessment of an individual's physical activity level, with a moderate degree of reproducibility.

To study the effects of a 12-week continuous aerobic exercise program without energy restriction on intrahepatic fat, indices of liver function (aspartate aminotransferase [AST], alanine aminotransferase [ALT] and γ-glutamyl transpeptidase [γGTP]), plasminogen activator inhibitor-1 (PAI-1) and insulin resistance (HOMA-IR).Subjects were divided into two groups based on the degree of intrahepatic fat accumulation at baseline (high liver fat [HLF]: n = 13; low liver fat [LLF]: n = 14). Participants were instructed to exercise for more than 300 min per week at the lactate threshold. Fat accumulation (intramuscular, intrahepatic, visceral and subcutaneous fat) was evaluated by computed tomography. Blood samples were taken to determine the levels of AST, ALT, PAI-1, glucose and insulin.Weight, body mass index, body fat, visceral fat and subcutaneous fat decreased significantly in both groups between baseline and post-intervention (P0.05), but were not significantly different between the two groups (P0.05). Intrahepatic fat, AST, ALT and PAI-1 improved significantly between baseline and post-intervention in the HLF group (P0.05; AST, P = 0.052), and improvements were significantly greater than those in the LLF group (P0.05). γGTP decreased significantly in the HLF group between baseline and post-intervention (P0.05), but was not significantly different between the two groups (P0.05). HOMA-IR did not significantly improve between baseline and post-intervention either within or between the two groups (P0.05).This study revealed that a 12-week continuous aerobic exercise program without energy restriction might improve intrahepatic fat, liver function and atherosclerosis-related factors.

Recent analytical methods such as real-time polymerase chain reaction (PCR) and Western blotting have now enabled us to analyze the gene and protein expression from small amounts of tissue. A fine needle muscle biopsy is thus expected to obtain a minimally sufficient amount of skeletal muscle to make a successful analysis. As a result, we used this fine needle muscle biopsy technique to obtain muscle tissue specimens from the vastus lateral muscle in 40 participants. The amount of tissue obtained by the fine needle was 5.2 +/- 3.2 mg (mean +/- standard deviation). The total RNA extracted was 3.0 +/- 1.4 microg and the total protein extracted was 2203 +/- 1541 microg. Furthermore, the skeletal muscle tissue specimens obtained by the regular needle technique and blood sample were used as the control. Those specimens were used to measure the gene expression of beta-myosin heavy chain slow (beta-MHC slow) by real-time PCR and the protein expression of monocalboxylate transporter 1 (MCT-1) by Western blotting. Beta-MHC slow gene expression was detected in both samples obtained by a fine and a regular needle biopsy, but not in a blood sample. Furthermore, the MCT-1 protein was detected in samples obtained by a fine needle muscle biopsy. These results indicated that the fine needle muscle biopsy is therefore a useful technique to obtain skeletal muscle specimens at least to analyze the gene and protein expression.