Impact of Intergenerational Shokuiku (Food and Nutrition Education) Programs on Alleviating Loneliness in Japanese Communities across Ages.

As loneliness is a risk factor for mental and physical health problems in various age groups, this study aimed to explore the impact of the intergenerational Shokuiku (food and nutrition education) program (IGSP) on loneliness in a Japanese community. This single-arm intervention study conducted between 2022 and 2023 included children (n = 21), guardians (n = 16), university students (n = 3), and older adults (n = 6). The IGSP was a one-day program that included participants making and eating their own bread, butter, and sorbet. Loneliness was measured using the Five-item Loneliness Scale for Children (Five-LSC; Japanese) and the three-item UCLA Loneliness Scale (Japanese; for adults) with other direct questions. Social capital, including civic participation, social cohesion, and reciprocity, was assessed using a self-administered questionnaire. The Five-LSC score significantly decreased post-intervention (p = 0.04). There was a significant increase in adults who reported not feeling lonely (p = 0.001). However, the UCLA Loneliness Scale scores did not show any significant changes. A positive change in social cohesion, including community contribution (p = 0.001) and attachment (p = 0.002), was observed among adults. This study suggests that IGSPs have a positive impact on loneliness in children and a partly positive one in adults. These findings emphasize the potential of intergenerational programs to reduce loneliness in communities.

Effects of substituting sedentary time with physical activity on body mass index in Japanese adults with Down syndrome: A cross-sectional study.

Objective: and Rationale: Obesity is a health challenge for adults with Down syndrome. Therefore, a physical activity promotion program is required to prevent or reduce obesity in adults with this condition. However, there is a lack of evidence of useful risk reduction initiatives. The objective of this study was to suggest a rationale for behaviors that should replace time of inactivity to reduce obesity in Japanese adults with Down syndrome. Methods: The participants were adults with Down syndrome, aged 18-48 years, living in Japan. The snowball sampling method was used. To detect an effect size of 0.20 for body mass index using an F-test, 80 participants were required, generating a statistical power of 0.8 and a risk level of 0.05. Survey items included sex, age, height, weight, body mass index, and physical activity (min/d). Physical activity was categorized by intensity and further divided into ambulatory and non-ambulatory activities. The body mass index categories were compared using analysis of covariance. An isotemporal substitution model was used to confirm the interdependence of behaviors. Results: Half of the participants were obese, with a body mass index of 25 kg/m2 or higher. The obese group had significantly fewer light physical activity, moderate-to-vigorous physical activity, and ambulatory moderate-to-vigorous physical activity times than the non-obese group. Replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity was significantly associated with a lower body mass index. Conclusions: This study suggests a rationale for behaviors that should replace time of inactivity to reduce obesity in adults with Down syndrome. Specifically, replacing 10 min of sedentary behavior with ambulatory moderate-to-vigorous physical activity time may contribute to obesity reduction.

A Community-Based Intervention to Enhance Subjective Well-Being in Older Adults: Study Design and Baseline Participant Profiles.

Promoting subjective well-being is a crucial challenge in aging societies. In 2022, we launched a community-based intervention trial (the Chofu-Digital-Choju Movement). This initiative centered on fostering in-person and online social connections to enhance the subjective well-being of older adults. This paper describes the study design and baseline survey. This quasi-experimental study involved community-dwelling older adults aged 65-84 years in Chofu City, Tokyo, Japan. A self-administered questionnaire was distributed to 3742 residents (1681 men and 2061 women), and a baseline survey was conducted in January 2022. We assessed subjective well-being (primary outcome); psychosocial, physical, and dietary factors; and the use of information and communication technology variables (secondary outcomes) among the participants. After the intervention involving online classes, community hubs, and community events, a 2-year follow-up survey will be conducted to evaluate the effects of the intervention, comparing the intervention group (participants) with the control group (non-participants). We received 2503 questionnaires (66.9% response rate); of these, the analysis included 2343 questionnaires (62.6% valid response rate; mean age, 74.4 (standard deviation, 5.4) years; 43.7% male). The mean subjective well-being score was 7.2 (standard deviation, 1.9). This study will contribute to the development of a prototype subjective well-being strategy for older adults.

The Amount of Light to Vigorous Physical Activity (Met's-Hours/Day) in Children with and without Down Syndrome Attending Elementary School in Japan.

Children with Down syndrome (DS) have physical characteristics such as hypotonus of the musculature. Therefore, their attainment rate of physical activity guidelines is low, and guidelines alone may not be sufficient in assessing the amount of physical activity in children with DS. Compared with normal children (NC) of the same grade, light physical activity (LPA) must be considered while assessing physical activity of children with DS, owing to muscle hypotonia. This study included 69 children with DS and 68 NC in grades 4−6 attending elementary school in Japan. The measurements for physical characteristics included age, height, weight, and body mass index. Physical activity was measured using a triaxial accelerometer, which indicated physical activity volume. Children with DS had less moderate-to-vigorous physical activity duration (DS: 53.1 min/day, NC: 65.0 min/day; p < 0.001) but significantly longer LPA duration (DS: 376.4 min/day, NC: 287.7 min/day; p < 0.001) than NC. Conversely, the amount of light to vigorous physical activity (Met's-hours/day) was greater in children with DS (DS: 16.0 Met's-hours/day, NC: 14.4 Met's-hours/day; p = 0.037). In children with DS with muscular hypotonia, vigorous physical activity is challenging, but LPA is feasible. Developing and validating educational programs that promote physical activity with intensity level depending on individual's physical characteristic are warranted.

Changes in physical activity patterns of students from primary to secondary school: a 5-year longitudinal study.

This study aimed to annually examine anthropometric characteristics and physical activity (PA) among children transitioning from fourth grade (9-10 years of age) to eighth grade (13-14 years of age) in Japan. The participants' (n = 63) age, grade, sex, weight, height, and weight status were recorded at baseline. Accelerometry assessments were performed annually following established protocols. Time spent on activities requiring ≥ 3 metabolic equivalents (METs), 1.6-2.9 METs, and ≤ 1.5 METs were defined as moderate-to-vigorous intensity PA (MVPA), light PA (LPA), and sedentary behavior (SB), respectively. Two linear mixed models were used to examine whether MVPA, LPA, and SB min/day changed over time. Fifty-five participants provided complete data. A significant, nonlinear, longitudinal decline in MVPA, an increase in SB, and a linear decline in LPA were observed. Changes in MVPA and SB were accelerated in seventh grade (12-13 years of age). Male sex and maintenance of normal weight status were associated with higher MVPA levels. Changes in LPA and SB were not associated with sex or weight status. During the transition period from primary to secondary school, MVPA and SB showed nonlinear accelerations. Sex and normal weight were associated with more time spent performing MVPA.

[Situation of food assistance users and the association with change in socioeconomic status during COVID-19 pandemic in Japan].

Objective　This study aimed to understand the situation of the users of food assistance activities during the COVID-19 pandemic, and to examine the relationship with the changes in socioeconomic conditions.Methods　A total of 33,004 (16,065 men and 16,939 men) people aged 20 or older who cooperated with an online survey in February 2021 were included in the analysis. The analysis was conducted by classifying users of one of the following types of food assistance as food assistance users and other users as non-users: eating on site (e.g., children's cafeteria), receiving food at a specific location (e.g., food pantry), or having food delivered to their home (e.g., emergency home food delivery). A multiple logistic regression analysis was used to calculate the adjusted odds ratios (95% confidence interval (CI)) for the association between food assistance use and changes in socioeconomic status, which was assessed based on the employment status and household monthly income just before and during the COVID-19 pandemic.Results　The number of users of food assistance was 3,071 (9.3%). Of these, 1,549 (4.7%) were users of children's cafeterias, 1,296 (3.9%) were users of food pantries, and 2,236 (6.8%) were users of emergency home food delivery (with duplicate responses). The adjusted odds ratio for food assistance use was 1.47 (95% CI 1.28-1.70) for those with changes in employment status compared to those with no changes. The adjusted odds ratio for food assistance use was 1.89 (1.65-2.15) for those with reduced income and 1.67 (1.37-2.03) for those with increased household income compared to those with no changes. The adjusted odds ratios for food assistance use were higher for those with changes in employment status and/or household income than those with no changes in both.Conclusions　One in ten individuals used food assistance during the COVID-19 pandemic. It was suggested that many of the users of food assistance had changed their employment status or household income during the COVID-19 pandemic. In the future, it will be necessary to establish a public-private system that can provide information on local food assistance to people whose socioeconomic status has changed rapidly.

Assessment of Physical Activity and Related Factors among Adults with Visual Impairments in Japan.

In Japan, there is a lack of physical activity data on health and disease among people with visual impairments, making it difficult to develop specific strategies for health promotion. This study aimed to identify moderate-to-vigorous physical activity (MVPA) among people with visual impairments in Japan, to examine the percentage of them who meet the MVPA recommended activity, and to identify factors related to MVPA. In this cross-sectional study, we analyzed a survey of 169 adults with visual impairments. The relationship between MVPA and related factors was analyzed using binomial logistic regression analysis. The median MVPA was 46 min/day for men and 36 min/day for women, respectively, aged < 65 years, and 26 min/day for men and 34 min/day for women, respectively, aged ≥ 65 years. Seventy-eight percent of the subjects achieved the recommendations by the WHO, and 28% of the subjects < 65 years had achieved the MVPA of 60 min/day recommended by the Japanese Active Guide. Self-efficacy (SE) for PA, recommended PA implementation behavior, subjective walking speed, and exercise habits were significantly associated with MVPA. The current status of MVPA time among people with visual impairments in Japan, as revealed by this study, indicates that it is important to set realistic goals and plan a step-by-step process to achieve the recommendation. In the future, it will be important to develop a program that encourages the improvement of SE and promotes PA.

Effects of Visual Flow Alterations on Psychophysiological Responses to Virtual Reality Exercise.

Virtual reality (VR) technology combined with exercise, called VR exercise, is believed to have beneficial effects on mood; but VR factors contributing to improved mood remain ambiguous. The purpose of this study was to examine the effect of visual flow speed on psychophysiological responses (i.e., physiological responses, ratings of perceived exertion or RPE, and mood) to immersive VR exercise in a simulated natural environment. Eighteen male participants (Mage =23.1, SD = 1.9 years) cycled an ergometer at 80 watts for 5 minutes on three separate occasions while watching a first-person VR movie through VR goggles at three different speeds of visual flow, corresponding to 7.5 km.h-1, 15 km.h-1, and 22.5 km.h-1. The order of the three speeds was randomized in a counterbalanced design. We measured heart rate, oxygen uptake, minute ventilation, respiratory rate, and cadence during the exercise, and we recorded ratings of perceived exertion (RPE) and mood immediately after the exercise. We evaluated mood states with the Two-Dimensional Mood Scale. One-way repeated measures analysis of variance or the Friedman test revealed no significant effects on any physiological variables, RPE or cadence as a result of altered visual flow speed during VR exercise (p > .05). However, speed of visual flow significantly influenced participant ratings of Vitality (p = 0.01) and Pleasure (p = 0.02), with the faster speed resulting in a more positive mood state. As these findings showed that VR exercise with faster visual flow induced positive mood states, we recommend faster visual flow to induce better mood states in VR exercise.

The association between obesity and sedentary behavior or daily physical activity among children with Down's syndrome aged 7-12 years in Japan: A cross-sectional study.

BACKGROUND: An assessment of the adverse health effects of obesity in children with Down's syndrome (DS) is required to develop programs that facilitate the acquisition of healthy behaviors. Individuals with DS are often obese. These individuals must develop health related behaviors in childhood. For this reason, it is necessary to clarify the factors associated with obesity in children with DS. AIMS: This study had two purposes. The first was to assess the obesity and to evaluate the sedentary behavior (SB) and physical activity of Japanese elementary school children with Down's syndrome. The second was to investigate the association between obesity and SB or moderate to vigorous physical activity (MVPA). METHODS AND PROCEDURES: Ninety-three children (male/female: 51/42) with DS in elementary school grades 1 to 6 (aged 7-12 years) participated in this study in Japan. Physical characteristics were obtained from the questionnaire completed by their parents. The questionnaire provided information on regular school checkups. SB and MVPA were evaluated using a triaxial accelerometer. RESULTS: Approximately 20% of the children with DS were obese. Nearly half of the children with DS achieved 60 min of MVPA. SB time was significantly longer in the upper grades (aged 11-12 years) than in the lower grades (aged 7-8 years). Comparing weekdays and weekend days, the middle (aged 9-10 years) and upper grades had significantly shorter MVPA times on weekend days. The frequency of obesity was significantly associated with shorter MVPA times in the lower grades and longer SB time in the middle grades. CONCLUSIONS AND IMPLICATIONS: Children with DS may increase their SB time as their age group (grade category) increases. Increasing opportunities for MVPA during weekends may increase physical activity. The observed relationship between obesity and SB time or MVPA time may apply only to younger and middle grade children with DS. Further investigation is necessary to confirm these relationships.

Accuracy of 12 Wearable Devices for Estimating Physical Activity Energy Expenditure Using a Metabolic Chamber and the Doubly Labeled Water Method: Validation Study.

BACKGROUND: Self-monitoring using certain types of pedometers and accelerometers has been reported to be effective for promoting and maintaining physical activity (PA). However, the validity of estimating the level of PA or PA energy expenditure (PAEE) for general consumers using wearable devices has not been sufficiently established. OBJECTIVE: We examined the validity of 12 wearable devices for determining PAEE during 1 standardized day in a metabolic chamber and 15 free-living days using the doubly labeled water (DLW) method. METHODS: A total of 19 healthy adults aged 21 to 50 years (9 men and 10 women) participated in this study. They followed a standardized PA protocol in a metabolic chamber for an entire day while simultaneously wearing 12 wearable devices: 5 devices on the waist, 5 on the wrist, and 2 placed in the pocket. In addition, they spent their daily lives wearing 12 wearable devices under free-living conditions while being subjected to the DLW method for 15 days. The PAEE criterion was calculated by subtracting the basal metabolic rate measured by the metabolic chamber and 0.1×total energy expenditure (TEE) from TEE. The TEE was obtained by the metabolic chamber and DLW methods. The PAEE values of wearable devices were also extracted or calculated from each mobile phone app or website. The Dunnett test and Pearson and Spearman correlation coefficients were used to examine the variables estimated by wearable devices. RESULTS: On the standardized day, the PAEE estimated using the metabolic chamber (PAEEcha) was 528.8±149.4 kcal/day. The PAEEs of all devices except the TANITA AM-160 (513.8±135.0 kcal/day; P>.05), SUZUKEN Lifecorder EX (519.3±89.3 kcal/day; P>.05), and Panasonic Actimarker (545.9±141.7 kcal/day; P>.05) were significantly different from the PAEEcha. None of the devices was correlated with PAEEcha according to both Pearson (r=-.13 to .37) and Spearman (ρ=-.25 to .46) correlation tests. During the 15 free-living days, the PAEE estimated by DLW (PAEEdlw) was 728.0±162.7 kcal/day. PAEE values of all devices except the Omron Active style Pro (716.2±159.0 kcal/day; P>.05) and Omron CaloriScan (707.5±172.7 kcal/day; P>.05) were significantly underestimated. Only 2 devices, the Omron Active style Pro (r=.46; P=.045) and Panasonic Actimarker (r=.48; P=.04), had significant positive correlations with PAEEdlw according to Pearson tests. In addition, 3 devices, the TANITA AM-160 (ρ=.50; P=.03), Omron CaloriScan (ρ=.48; P=.04), and Omron Active style Pro (ρ=.48; P=.04), could be ranked in PAEEdlw. CONCLUSIONS: Most wearable devices do not provide comparable PAEE estimates when using gold standard methods during 1 standardized day or 15 free-living days. Continuous development and evaluations of these wearable devices are needed for better estimations of PAEE.

Assessment of energy expenditure using doubly labeled water, physical activity by accelerometer and reported dietary intake in Japanese men with type 2 diabetes: A preliminary study.

The aim of the present study was to determine the total energy expenditure, physical activity and dietary intake of men with type 2 diabetes mellitus and control participants without type 2 diabetes mellitus who were matched for age and body mass index. The participants in the present study were 12 well-controlled type 2 diabetes mellitus patients and 10 controls, aged 40-75 years, with a body mass index <30 kg/m2 . Total energy expenditure under free-living conditions was assessed using the doubly labeled water method, and physical activity was measured using a triaxial accelerometer. Dietary intake was assessed using a self-recorded food intake diary during the measurement period. Participants were instructed to record their dietary intake over 3 days, including 2 weekdays. Total energy expenditure was not significantly different between the groups (P = 0.153), nor were energy (P = 0.969) or macronutrient intakes. In conclusion, when age and body mass index are matched, total energy expenditure and self-reported energy intake are not significantly different between type 2 diabetes mellitus patients and healthy controls.

[Evaluation of Worker's Living Activity-time Questionnaire (JNIOSH-WLAQ) primarily to assess workers' sedentary behavior].

OBJECTIVES: The National Institute of Occupational Safety and Health, Japan (JNIOSH) developed a new Worker's Living Activity-time Questionnaire (JNIOSH-WLAQ) which primarily evaluates workers' sedentary behavior. The purpose of this study was to investigate the test-retest reliability and criterion validity of the WLAQ. METHODS: One hundred and thirty eight workers completed the WLAQ twice in one week. During the week, they wore a thigh-worn inclinometer (activPAL) and maintained a daily log as criteria measurements. The WLAQ measures working time, commuting time, daily rest period (DRP), sleeping time, and time spent sitting within the four typical domains of a worker's life: (a) working time, (b) commuting time, (c) non-working time on a workday, and (d) non-workday. We calculated intraclass correlation coefficients (ICC) as a reliability value and Spearman's ρ as a validity value. Bland-Altman plots were used to assess any bias. RESULTS: The analysis of WLAQ indicated favorable ICCs (0.72-0.98) for all living activity-times. The WLAQ had "strong" ρ values for working time (0.80) and DRP (0.83), a "very strong" ρ value for commuting time (0.96), and "moderate" ρ values for sleeping time during a workday (0.69) and a non-workday (0.53). As for the sitting time, the WLAQ had "moderate" ρ values for working time (0.67) and non-working time on a workday (0.59), a "strong" ρ value for commuting time (0.82), and a "low" ρ value for a non-workday (0.40). Bland-Altman plots showed a significant fixed bias for sitting time during working time and significant fixed and proportional biases for sitting time on a non-workday. CONCLUSIONS: The study showed that the WLAQ has acceptable measurement features, which makes this questionnaire a reliable resource for future epidemiological surveys.

Percentage-Method Improves Properties of Workers' Sitting- and Walking-Time Questionnaire.

BACKGROUND: Does asking for the percentage of time spent sitting during work (P-method) instead of asking for the absolute length of time spent sitting (T-method) improve properties of the workers' sitting- and walking-time questionnaire (WSWQ)? The purpose of this study was to investigate whether questioning technique influences test-retest reliability and criterion validity of the WSWQ. METHODS: Sixty-five Japanese workers completed each version of the WSWQ in random order. Both questionnaires assessed quantities of time spent sitting or walking (including standing) during work time, non-working time on a workday, and anytime on a non-workday. Participants wore the thigh-worn inclinometer (activPAL) as criterion measure. Intraclass correlation coefficients (ICC) and Spearman's ρ were used for the analyses. RESULTS: For all three domains, values of reliability and validity with the P-method tended to be higher than with the T-method: ICC values ranged from 0.48-0.85 for the T-method and from 0.71-0.85 for the P-method; Spearman's ρ values ranged from 0.25-0.58 for the T-method and from 0.42-0.65 for the P-method. The validities with both methods on a workday (0.51-0.58 for the T-method and 0.56-0.65 for the P-method) were higher than validities on a non-workday (0.25-0.45 for the T-method and 0.42-0.60 for the P-method). In post-survey interviews, 48 participants (77%) chose the P-method as their preferred questioning style. CONCLUSIONS: The study revealed that the P-method WSWQ had better reliability, validity, and ease of answering than the T-method, suggesting that the P-method can improve properties of the WSWQ and consequently advance the quality of epidemiological surveys in this field.

Validity and reproducibility of a novel method for time-course evaluation of diet-induced thermogenesis in a respiratory chamber.

We developed a novel method for computing diet-induced thermogenesis (DIT) in a respiratory chamber and evaluated the validity and reproducibility of the method. We hypothesized that DIT may be calculated as the difference between postprandial energy expenditure (EE) and estimated EE (sum of basal metabolic rate and physical activity (PA)-related EE). The estimated EE was derived from the regression equation between EE from respiration and PA intensity in the fasting state. It may be possible to evaluate the time course of DIT using this novel technique. In a validity study, we examined whether DIT became zero (theoretical value) for 6 h of fasting in 11 subjects. The mean value of DIT calculated by the novel and traditional methods was 22.4 ± 13.4 and 3.4 ± 31.8 kcal/6 h, respectively. In the reproducibility study, 15 adult subjects lived in the respiratory chamber for over 24 h on two occasions. The DIT over 15 h of postprandial wake time was calculated. There were no significant differences in the mean values of DIT between the two test days. The within-subject day-to-day coefficient of variation for calculated DIT with the novel and traditional methods was approximately 35% and 25%, respectively. The novel method did not have superior reproducibility compared with that of the traditional method. However when comparing the smaller variation in the fasting state than the theoretical value (zero), the novel method may be better for evaluating interindividual differences in DIT than the traditional method and also has the ability to evaluate the time-course.

Evaluation of active video games intensity: comparison between accelerometer-based predictions and indirect calorimetric measurements.

BACKGROUND: Several active video game (AVG) intervention studies failed in showing an increase in physical activity by using accelerometry measurements. OBJECTIVE: To test the validity of accelerometry for monitoring AVG playing intensity. METHOD: Twenty-two adults performed 80 activities included in the Wii Sports and Wii Fit Plus series. The energy expenditure (EE) and subsequent MET values were measured by indirect calorimetry using metabolic chambers. Subjects wore an accelerometer-based monitor displaying MET values. For each activity, METs values obtained from indirect calorimetry and accelerometry were compared. Each activity was classified as light or moderate to vigorous physical activity (LPA: < 3METs or MVPA: ⩾ 3METs) for the two methods. RESULTS: AVG intensities have been slightly but significantly underestimated by the acceleromater-based monitor compared to the indirect calorimetry (2.5 ± 1.0 instead of 2.7 ± 0.9 METs). Fourty percent of activities have been significantly misestimated, and 20% have been misclassified. CONCLUSION: Those results point out the potential bias of accelerometry measurements for evaluating AVG intensities. Because average AVG intensity lays at the boundary between LPA and MVPA classes, misclassifications can frequently occur. Accelerometry data should be interpreted with caution in intervention studies using AVG.

Prediction models discriminating between nonlocomotive and locomotive activities in children using a triaxial accelerometer with a gravity-removal physical activity classification algorithm.

The aims of our study were to examine whether a gravity-removal physical activity classification algorithm (GRPACA) is applicable for discrimination between nonlocomotive and locomotive activities for various physical activities (PAs) of children and to prove that this approach improves the estimation accuracy of a prediction model for children using an accelerometer. Japanese children (42 boys and 26 girls) attending primary school were invited to participate in this study. We used a triaxial accelerometer with a sampling interval of 32 Hz and within a measurement range of ±6 G. Participants were asked to perform 6 nonlocomotive and 5 locomotive activities. We measured raw synthetic acceleration with the triaxial accelerometer and monitored oxygen consumption and carbon dioxide production during each activity with the Douglas bag method. In addition, the resting metabolic rate (RMR) was measured with the subject sitting on a chair to calculate metabolic equivalents (METs). When the ratio of unfiltered synthetic acceleration (USA) and filtered synthetic acceleration (FSA) was 1.12, the rate of correct discrimination between nonlocomotive and locomotive activities was excellent, at 99.1% on average. As a result, a strong linear relationship was found for both nonlocomotive (METs = 0.013×synthetic acceleration +1.220, R2 = 0.772) and locomotive (METs = 0.005×synthetic acceleration +0.944, R2 = 0.880) activities, except for climbing down and up. The mean differences between the values predicted by our model and measured METs were -0.50 to 0.23 for moderate to vigorous intensity (>3.5 METs) PAs like running, ball throwing and washing the floor, which were regarded as unpredictable PAs. In addition, the difference was within 0.25 METs for sedentary to mild moderate PAs (<3.5 METs). Our specific calibration model that discriminates between nonlocomotive and locomotive activities for children can be useful to evaluate the sedentary to vigorous PAs intensity of both nonlocomotive and locomotive activities.

The relationship of body composition to daily physical activity in free-living Japanese adult men.

The objective of the present study was to investigate whether a previously reported apparent negative relationship between fat mass and daily physical activity in Japanese adult women would also be observed in Japanese adult men. The subjects were grouped into quartiles of BMI and body fat percentage (%BF). The number of steps walked each day and the duration of light- to vigorous-intensity physical activity were assessed by an accelerometer over the same period of time as for the doubly labelled water experiment. The results showed that BMI negatively correlated with the number of steps and time spent in moderate-intensity physical activity, whereas %BF showed a negative relationship with physical activity-related energy expenditure (PAEE)/body weight (BW) and physical activity level. The analysis of data using %BF quartiles revealed that PAEE/BW decreased from the second quartile in which the BMI was < 25 kg/m2. These observations are similar to those reported in our previous study in Japanese adult women. These cross-sectional studies cannot prove causality, and that obesity causes physical inactivity may be the case. However, the results of the present study provide information regarding which physical activity variables should be used in longitudinal studies.

Effects of intermittent physical activity on fat utilization over a whole day.

PURPOSE: We examined whether continuous and intermittent physical activity (PA) differentially influence fat utilization. METHODS: This was a randomized crossover study. Nine healthy young male participants performed two 39-h (two nights, three days) PA sessions (continuous and intermittent exercise) in a respiratory chamber to measure energy expenditure (EE) and substrate oxidation. Participants used a stationary cycling ergometer continuously for 40 min and then 45 min in the continuous PA trial and for 5 min every 30 min 17 times in the intermittent PA trial. They consumed high-carbohydrate meals corresponding to predicted daily total EE for 3 d before entering the respiratory chamber and four high-fat meals corresponding to predicted total EE in the chamber. RESULTS: Twenty-three-hour RER adjusted for sleeping RER on the preceding day was significantly lower in the intermittent PA trial than that in the continuous PA trial (P = 0.021). Twenty-three-hour RER adjusted for sleeping RER on the preceding day was correlated with accumulated consecutive minutes of METs ≤ 1.5 (3 min or more, r = 0.477; 5 min or more, r = 0.510; 10 min or more, r = 0.605). CONCLUSIONS: The intermittent PA trial induced greater fat utilization than the continuous PA trial. The present study, therefore, suggests that intermittent PA has a beneficial effect on 24-h fat oxidation after consumption of a high-fat meal, which may help prevent weight gain over time.

Effects of increased meal frequency on fat oxidation and perceived hunger.

OBJECTIVE: Consuming smaller, more frequent meals is often advocated as a means of controlling body weight, but studies demonstrating a mechanistic effect of this practice on factors associated with body weight regulation are lacking. The purpose of this study was to compare the effect of consuming three (3M) vs. six meals (6M) per day on 24-h fat oxidation and subjective ratings of hunger. DESIGN AND METHODS: Lean (body mass index <25 kg/m(2) ) subjects (7M, 8F) were studied in a whole-room calorimeter on two occasions in a randomized cross-over design. Subjects were provided isoenergetic, energy balanced diets with a 1- to 2-week washout between conditions. Hunger, fullness, and "desire to eat" ratings were assessed throughout the day using visual analog scales and quantified as area under the curve (AUC). RESULTS: There were no differences (P < 0.05) in 24-h energy expenditure (8.7 ± 0.3 vs. 8.6 ± 0.3 mj d(-1) ), 24-h respiratory quotient (0.85 ± 0.01 vs. 0.85 ± 0.01), or 24-h fat oxidation (82 ± 6 vs. 80 ± 7 g day(-1) ) between 3M and 6M, respectively. There was no difference in fullness 24-h AUC, but hunger AUC (41850 ± 2255 vs. 36612 ± 2556 mm.24 h, P = 0.03) and "desire to eat" AUC (47061 ± 1791 vs. 41170 ± 2574 mm.24 h, P = 0.03) were greater during 6M than 3M. CONCLUSION: We conclude that increasing meal frequency from three to six per day has no significant effect on 24-h fat oxidation, but may increase hunger and the desire to eat.

Cardiorespiratory fitness level correlates inversely with excess post-exercise oxygen consumption after aerobic-type interval training.

BACKGROUND: The purpose of this study was to reveal any association between cardiorespiratory fitness level and excess post-exercise oxygen consumption (EPOC) using three cycling protocols with varying degrees of exercise intensity, i.e., sprint interval training (SIT), high-intensity interval aerobic training (HIAT), and continuous aerobic training (CAT). FINDINGS: Ten healthy men, aged 20 to 31 years, attended a cross-over experiment and completed three exercise sessions: SIT consisting of 7 sets of 30-s cycling at 120% VO2max with a 15-s rest between sets; HIAT consisting of 3 sets of 3-min cycling at 80~90% VO2max with a 2-min active rest at 50% VO2max between sets; and CAT consisting of 40 min of cycling at 60~65% VO2max. During each session, resting VO2, exercise VO2, and a 180-min post-exercise VO2 were measured. The net exercise VO2 during the SIT, HIAT, and CAT averaged 14.7 ± 1.5, 31.8 ± 4.1, and 71.1 ± 10.0 L, and the EPOCs averaged 6.8 ± 4.0, 4.5 ± 3.3, and 2.9 ± 2.8 L, respectively. The EPOC with SIT was greater than with CAT (P < 0.01) and HIAT (P = 0.12). Correlation coefficients obtained between subjects' VO2max and the ratio of EPOC to net exercise VO2 for SIT, HIAT, and CAT were -0.61 (P = 0.06), -0.79 (P < 0.01), and -0.42 (P = 0.23), respectively. CONCLUSIONS: Our data suggest that cardiorespiratory fitness level correlates negatively with the magnitude of EPOC, especially when performing aerobic-type interval training.