How do previously inactive individuals restructure their time to 'fit in' morning or evening exercise: a randomized controlled trial.

The objective of this study was to investigate changes in sedentary and active behaviors when previously inactive adults start exercising in the morning or evening. One-hundred adults with overweight or obesity (BMI ≥ 25 kg/m2) were recruited for a 12-week intervention and randomized to one of three groups: (i) morning exercise (AMEx; 0600-0900); (ii) evening exercise (PMEx; 1600-1900); or (iii) waitlist control. AMEx and PMEx were prescribed self-paced aerobic exercise to achieve a weekly total of 250 min via a combination of supervised and unsupervised training. Sedentary and active behavior times were measured at baseline, mid- and post-intervention using the multimedia activity recall for children and adults. Time spent engaging in physical activity was significantly increased from baseline at both mid- (+ 14-22 min·day-1) and post-intervention (+ 12-19 min·day-1), for AMEx and PMEx. At 12-weeks, participants in both morning and evening exercise groups reported increased time spent Sleeping (+ 36 and + 20 min·day-1, respecitively), and reduced time spent watching TV/playing videogames (- 32 and - 25 min·day-1, respectively). In response to an exercise stimulus, previously inactive adults make encouraging modifications in how they use their time, and the patterns of change are similar with morning and evening exercise.

High intensity interval training does not result in short- or long-term dietary compensation in cardiac rehabilitation: Results from the FITR heart study.

The aim of this study was to investigate short- and long-term compensatory effects on dietary intake following high intensity interval training (HIIT) compared with usual care moderate intensity continuous training (MICT) during and following a cardiac rehabilitation program. This study investigates secondary outcomes of a clinical trial. Ninety-three participants with coronary artery disease enrolled in a 4-week cardiac rehabilitation program, were randomised to 1) 4x4-minute HIIT; or 2) 40-min of MICT (usual care). Patients were instructed to complete 3 weekly sessions (2 supervised, 1 home-based) for 4-weeks, and 3 weekly home-based sessions thereafter for another 48-weeks. Dietary intake was measured by telephone-based 24-h recall over 2 day at baseline, 4-weeks, 3-months, 6-months, and 12-months. Three-Factor Eating Questionnaire was used to measure dietary behaviour and Leeds Food Preference Questionnaire used to measure food preferences. Appetite was assessed by a visual analogue scale and appetite-regulating hormones. There was no change over the study period or differences between groups for daily energy intake at 4-weeks or 12-months. There were also no group differences for any other measures of dietary intake, fasting hunger or appetite-related hormones, dietary behaviour, or food preferences. These findings suggest that compared to moderate intensity exercise, HIIT does not result in compensatory increases of energy intake or indicators of poor diet quality. This finding appears to be the same for patients with normal weight and obesity. HIIT can therefore be included in cardiac rehabilitation programs as an adjunct or alterative to MICT, without concern for any undesirable dietary compensation.

A dual-process psychobiological model of temperament predicts liking and wanting for food and trait disinhibition.

A dual-process model of temperament, incorporating the Behavioural Inhibition System (BIS), Behavioural Activation System (BAS) and effortful control (EC), may help to predict hedonic responses to palatable food and trait disinhibition. PURPOSE: This study aimed to determine if the BIS, BAS and EC predicted liking and wanting for high-fat, sweet foods in adults with overweight and obesity, and if collectively, these variables predicted the eating behaviour trait of Disinhibition. METHODS: 168 adults (104 females, mean BMI = 33.3 kg/m2) completed the Three Factor Eating Questionnaire, the Carver and White BIS/BAS scales, the Adult Temperament Questionnaire-Effortful Control Scale - Short Form and the Leeds Food Preference Questionnaire. The strength of the BIS, BAS and EC in predicting wanting and liking for high-fat sweet foods, and trait Disinhibition was assessed using hierarchical multiple regression. RESULTS: Both the BIS and EC predicted liking, F (6, 161) = 5.05, p < .001, R2 = 0.16, and EC inversely predicted wanting, F (6, 161) = 3.28, p = .005, R2 = 0.11. The BIS, EC and liking predicted, F (8, 159) = 11.0, p < .001, R2 = 0.36, and explained 36% of Disinhibition. The BAS did not predict wanting, liking or Disinhibition. CONCLUSIONS: These results demonstrate that a sensitive BIS and a lower level of effortful control predicts food reward and Disinhibition in overweight and obese adults. Consequently, interventions that aim to increase effortful control and reduce BIS reactivity may be beneficial for reducing hedonically motivated, disinhibited eating behaviour.

Development and validation of the Child Three-Factor Eating Questionnaire (CTFEQr17).

OBJECTIVE: To develop and validate a child and adolescent version of the Three-Factor Eating Questionnaire (CTFEQr17) and to assess its psychometric properties and factor structure. We also examined associations between the CTFEQr17 and BMI and food preferences. DESIGN: A two-phase approach was utilized, employing both qualitative and quantitative methodologies. SETTING: Primary and secondary schools, UK. SUBJECTS: In phase 1, seventy-six children (thirty-nine boys; mean age 12·3 (sd 1·4) years) were interviewed to ascertain their understanding of the original TFEQr21 and to develop accessible and understandable items to create the CTFEQr17. In phase 2, 433 children (230 boys; mean age 12·0 (sd 1·7) years) completed the CTFEQr17 and a food preference questionnaire, a sub-sample (n 253; 131 boys) had their height and weight measured, and forty-five children (twenty-three boys) were interviewed to determine their understanding of the CTFEQr17. RESULTS: The CTFEQr17 showed good internal consistency (Cronbach's α=0·85) and the three-factor structure was retained: cognitive restraint (CR), uncontrolled eating (UE) and emotional eating (EE). Qualitative data demonstrated a high level of understanding of the questionnaire (95 %). High CR was found to be significantly associated with a higher body weight, BMI and BMI percentile. High UE and EE scores were related to a preference for high-fat savoury and high-fat sweet foods. The relationships between CTFEQr17, anthropometry and food preferences were stronger for girls than boys. CONCLUSIONS: The CTFEQr17 is a psychometrically sound questionnaire for use in children and adolescents, and associated with anthropometric and food preference measures.

Developing dimensions for a multicomponent multidisciplinary approach to obesity management: a qualitative study.

BACKGROUND: There have been consistent recommendations for multicomponent and multidisciplinary approaches for obesity management. However, there is no clear agreement on the components, disciplines or processes to be considered within such an approach. In this study, we explored multicomponent and multidisciplinary approaches through an examination of knowledge, skills, beliefs, and recommendations of stakeholders involved in obesity management. These stakeholders included researchers, practitioners, educators, and patients. METHODS: We used qualitative action research methods, including convergent interviewing and observation, to assist the process of inquiry. RESULTS: The consensus was that a multicomponent and multidisciplinary approach should be based on four central meta-components (patient, practitioner, process, and environmental factors), and specific components of these factors were identified. Psychologists, dieticians, exercise physiologists and general practitioners were nominated as key practitioners to be included. CONCLUSIONS: A complex condition like obesity requires that multiple components be addressed, and that both patients and multiple disciplines are involved in developing solutions. Implementing cycles of continuous improvement to deal with complexity, instead of trying to control for it, offers an effective way to deal with complex, changing multisystem problems like obesity.

Increasing Protein Distribution Has No Effect on Changes in Lean Mass During a Rugby Preseason.

Increasing the frequency of protein consumption is recommended to stimulate muscle hypertrophy with resistance exercise. This study manipulated dietary protein distribution to assess the effect on gains in lean mass during a rugby preseason. Twenty-four developing elite rugby athletes (age 20.1 ± 1.4 years, mass 101.6 ± 12.0 kg; M ± SD) were instructed to consume high biological value (HBV) protein at their main meals and immediately after resistance exercise while limiting protein intake between meals. To manipulate protein intake frequency, the athletes consumed 3 HBV liquid protein supplements (22 g protein) either with main meals (bolus condition) or between meals (frequent condition) for 6 weeks in a 2 × 2 crossover design. Dietary intake and change in lean mass values were compared between conditions by analysis of covariance and correlational analysis. The dietary manipulation successfully altered the protein distribution score (average number of eating occasions containing > 20 g of protein) to 4.0 ± 0.8 and 5.9 ± 0.7 (p < .01) for the bolus and frequent conditions, respectively. There was no difference in gains in lean mass between the bolus (1.4 ± 1.5 kg) and frequent (1.5 ± 1.4 kg) conditions (p = .91). There was no clear effect of increasing protein distribution from approximately 4-6 eating occasions on changes in lean mass during a rugby preseason. However, other dietary factors may have augmented adaptation.

Influence of habitual physical activity on gastric emptying in healthy males and relationships with body composition and energy expenditure.

Although a number of studies have examined the role of gastric emptying (GE) in obesity, the influences of habitual physical activity level, body composition and energy expenditure (EE) on GE have received very little consideration. In the present study, we compared GE in active and inactive males, and characterised relationships with body composition (fat mass and fat-free mass) and EE. A total of forty-four males (active n 22, inactive n 22; BMI 21-36 kg/m2; percentage of fat mass 9-42%) were studied, with GE of a standardised (1676 kJ) pancake meal being assessed by the [13C]octanoic acid breath test, body composition by air displacement plethysmography, RMR by indirect calorimetry, and activity EE (AEE) by accelerometry. The results showed that GE was faster in active compared with inactive males (mean half-time (t 1/2): active 157 (sd 18) and inactive 179 (sd 21) min, P< 0.001). When data from both groups were pooled, GE t 1/2 was associated with percentage of fat mass (r 0.39, P< 0.01) and AEE (r - 0.46, P< 0.01). After controlling for habitual physical activity status, the association between AEE and GE remained, but not that for percentage of fat mass and GE. BMI and RMR were not associated with GE. In summary, faster GE is considered to be a marker of a habitually active lifestyle in males, and is associated with a higher AEE level and a lower percentage of fat mass. The possibility that GE contributes to a gross physiological regulation (or dysregulation) of food intake with physical activity level deserves further investigation.

The effect of a whey protein supplement dose on satiety and food intake in resistance training athletes.

OBJECTIVE: Many athletes perform resistance training and consume dietary protein as a strategy to promote anabolic adaptation. Due to its high satiety value, the regular addition of supplemented dietary protein could plausibly displace other key macronutrients such as carbohydrate in an athlete's diet. This effect will be influenced by the form and dose of protein. Therefore, this study assessed the impact of liquid whey protein dose manipulation on subjective sensations of appetite and food intake in a cohort of athletes. DESIGN: Ten male athletes who performed both resistance and aerobic (endurance) training (21.2 ± 2.3 years; 181.7 ± 5.7 cm and 80.8 ± 6.1 kg) were recruited. In four counter-balanced testing sessions they consumed a manipulated whey protein supplement (20, 40, 60 or 80 g protein) 1 hour after a standardised breakfast. Subsequent energy intake was measured 3 hours after the protein supplement using an ad libitum test meal. Subjective appetite sensations were measured periodically during the test day using visual analogue scales. RESULTS: All conditions resulted in a significant decrease in ratings of hunger (50-65%; P < 0.05) at the time of supplement consumption. However, there were no significant differences between the conditions at any time point for subjective appetite sensations or for energy consumed in the ad libitum meal: 4382 ± 1004, 4643 ± 982, 4514 ± 1112, 4177 ± 1494 kJ respectively. CONCLUSION: Increasing whey protein supplement dose above 20 g did not result in a measurable increase in satiety or decrease in food intake. However, the inclusion of additional whey protein supplementation where not otherwise consumed could plausibly reduce dietary intake.

Reproducibility of subjective appetite ratings and ad libitum test meal energy intake in overweight and obese males.

BACKGROUND: To determine whether changes in appetite and energy intake (EI) can be detected and play a role in the effectiveness of interventions, it is necessary to identify their variability under normal conditions. We assessed the reproducibility of subjective appetite ratings and ad libitum test meal EI after a standardised pre-load in overweight and obese males. METHODS: Fifteen overweight and obese males (BMI 30.3 ± 4.9 kg/m(2), aged 34.9 ± 10.6 years) completed two identical test days, 7 days apart. Participants were provided with a standardised fixed breakfast (1676 kJ) and 5 h later an ad libitum pasta lunch. An electronic appetite rating system was used to assess subjective ratings before and after the fixed breakfast, and periodically during the postprandial period. EI was assessed at the ad libitum lunch meal. Sample size estimates for paired design studies were calculated. RESULTS: Appetite ratings demonstrated a consistent oscillating pattern between test days, and were more reproducible for mean postprandial than fasting ratings. The correlation between ad libitum EI on the two test days was r = 0.78 (P <0.01). Using a paired design and a power of 0.8, a minimum of 12 participants would be needed to detect a 10 mm change in 5 h postprandial mean ratings and 17 to detect a 500 kJ difference in ad libitum EI. CONCLUSION: Intra-individual variability of appetite and ad libitum test meal EI in overweight and obese males is comparable to previous reports in normal weight adults. Sample size requirements for studies vary depending on the parameter of interest and sensitivity needed.

Individual variability in compensatory eating following acute exercise in overweight and obese women.

BACKGROUND: While compensatory eating following acute aerobic exercise is highly variable, little is known about the underlying mechanisms that contribute to the alterations in exercise-induced eating behaviour. METHODS: Overweight and obese women (body mass index=29.6±4.0 kg/m(2)) performed a bout of cycling individually tailored to expend 400 kcal (EX) or a time-matched no exercise control condition in a randomised, counter-balanced order. 60 min after the cessation of exercise, an ad libitum test meal was provided. Substrate oxidation and subjective appetite ratings were measured during exercise/time-matched rest, and during the period between the cessation of exercise and food consumption. RESULTS: While ad libitum energy intake (EI) did not differ between EX and the control condition (666.0±203.9 vs 664.6±174.4 kcal, respectively; ns), there was a marked individual variability in compensatory EI. The difference in EI between EX and the control condition ranged from -234.3 to 278.5 kcal. Carbohydrate oxidation during exercise was positively associated with postexercise EI, accounting for 37% of the variance in EI (r=0.57; p=0.02). CONCLUSIONS: These data indicate that the capacity of acute exercise to create a short-term energy deficit in overweight and obese women is highly variable. Furthermore, exercise-induced CHO oxidation can explain a part of the variability in acute exercise-induced compensatory eating. Postexercise compensatory eating could serve as an adaptive response to facilitate the restoration of carbohydrate balance.

Interval training intensity affects energy intake compensation in obese men.

PURPOSE: Compensatory responses may attenuate the effectiveness of exercise training in weight management. The aim of this study was to compare the effect of moderate- and high-intensity interval training on eating behavior compensation. METHODS: Using a crossover design, 10 overweight and obese men participated in 4-week moderate (MIIT) and high (HIIT) intensity interval training. MIIT consisted of 5-min cycling stages at ± 20% of mechanical work at 45%VO(2)peak, and HIIT consisted of alternate 30-s work at 90%VO(2)peak and 30-s rests, for 30 to 45 min. Assessments included a constant-load exercise test at 45%VO(2)peak for 45 min followed by 60-min recovery. Appetite sensations were measured during the exercise test using a Visual Analog Scale. Food preferences (liking and wanting) were assessed using a computer-based paradigm, and this paradigm uses 20 photographic food stimuli varying along two dimensions, fat (high or low) and taste (sweet or nonsweet). An ad libitum test meal was provided after the constant-load exercise test. RESULTS: Exercise-induced hunger and desire to eat decreased after HIIT, and the difference between MIIT and HIIT in desire to eat approached significance (p = .07). Exercise-induced liking for high-fat nonsweet food tended to increase after MIIT and decreased after HIIT (p = .09). Fat intake decreased by 16% after HIIT, and increased by 38% after MIIT, with the difference between MIIT and HIIT approaching significance (p = .07). CONCLUSIONS: This study provides evidence that energy intake compensation differs between MIIT and HIIT.

A low-calorie meal replacement improves body composition and metabolic parameters in shift workers with overweight and obesity: a randomized, controlled, parallel group trial.

BACKGROUND: Shift work has been identified as a risk factor for several chronic health conditions including obesity. This study evaluated the impact of a low-calorie meal replacement (MR) as a dinner substitute on body composition and metabolic parameters in shift workers with overweight and obesity. METHODS: An 8-week parallel, randomized controlled trial was conducted on overweight and obese shift workers in a large hospital. An intervention group (IG) (n = 25) was provided with a low-calorie MR shake (∼200 kcal) as a replacement for dinner, every day for 8 weeks, while the control group (CG) (n = 25) continued their habitual diet. Anthropometric measurements, body composition, biochemical, and lifestyle data were assessed at the first and last visits. Analyses were done per protocol (PP) and by intention to treat (ITT). RESULTS: Over the study duration, both groups displayed moderate changes in anthropometric measurements and body composition, although these were not statistically significant according to the PP analysis. In the ITT analysis, apart from the hip circumference (HC), all other anthropometric parameters demonstrated significant group and time interactions, suggesting the advantageous effects of the meal replacement over the study period (P < 0.05). HDL and VLDL cholesterol measures showed significant main effects, influenced by both group (P = 0.031) and time (P = 0.050) respectively. The most pronounced dietary shift in the IG was a reduction in carbohydrate consumption and an increase in protein intake. Throughout the study, the meal replacement was well-tolerated, with no adverse events reported. CONCLUSIONS: The meal replacement dietary intervention appears to offer beneficial health effects over time. Extended research is crucial to understand the broader implications of meal replacements across diverse populations. TRIAL REGISTRATION: Australian New Zealand Clinical Trials Registry (ANZCTR): ACTRN12622000231741. Registered on 09 February 2022. https://www.anzctr.org.au/ACTRN12622000231741.aspx .

Methodological considerations for meal-induced thermogenesis: measurement duration and reproducibility.

Meal-induced thermogenesis (MIT) research findings have been highly inconsistent, in part, due to the variety of durations and protocols used to measure MIT. In the present study, we aimed to determine the following: (1) the proportion of a 6 h MIT response completed at 3, 4 and 5 h; (2) the associations between the shorter durations and the 6 h measures; (3) whether shorter durations improved the reproducibility of the measurement. MIT was measured in response to a 2410 kJ mixed composition meal in ten individuals (five males and five females) on two occasions. Energy expenditure was measured continuously for 6 h post-meal using indirect calorimetry, and MIT was calculated as the increase in energy expenditure above the pre-meal RMR. On average, 76, 89 and 96 % of the 6 h MIT response was completed within 3, 4 and 5 h, respectively, and MIT at each of these time points was strongly correlated with the 6 h MIT response (range for correlations, r 0·990-0·998; P< 0·01). The between-day CV for the 6 h measurement was 33 %, but it was significantly lower after 3 h of measurement (CV 26 %; P= 0·02). Despite variability in the total MIT between days, the proportion of MIT that was completed at 3, 4 and 5 h was reproducible (mean CV: 5 %). While 6 h are typically required to measure the complete MIT response, the 3 h measures provide sufficient information about the magnitude of the MIT response and may be applicable for testing individuals on repeated occasions.

The effect of shift work on different hematological parameters among healthcare workers.

Shift workers frequently experience alterations in their circadian rhythms, which are correlated with variations in hematological parameters. Changes in blood cells may be related to an individual's health status. Therefore, this study aimed to compare the relationship between shift work and changes in blood cells among a group of healthcare workers in Sri Lanka. A comparative cross-sectional study was conducted among healthcare workers, recruited by a stratified random sampling technique. Socio-demographic data were collected using a structured questionnaire. Venous blood samples were obtained and analyzed for the determination of total and differential blood cell counts. Descriptive statistics were used for the analysis of sociodemographic and hematological parameters. A sample of 37-day workers and 39 shift workers were included in the analysis. The mean ages (years) were not significantly different between the groups (36.8 ± 10.8 vs 39.1 ± 12.0; P = 0.371). Shift employees showed a significantly higher total mean white blood cell count (WBC) of 7548.75 mm-3 compared to day workers' 6869.19 mm-3 (P = 0.027). They also had higher mean absolute counts for all different WBC types (Neutrophils: 3949.2 vs 3557.7 , Lymphocyte: 2756.5 vs 2614.2 , Eosinophil: 317.6 vs 233.4 , Monocytes: 491.63 vs 432.51 , Basophils: 31.68 vs 29.22 ). Shift employees exhibited higher WBC counts than day workers at the same level of work experience. The length of shift work exposure revealed a positive link with neutrophil (r = 0.225 ) and eosinophil counts (r = 0.262 ), whereas these correlations were negative for day workers. Shift workers were associated with higher WBC counts in healthcare workers compared to their day-working counterparts.

A qualitative exploration of the experiences of shift workers participated in a low-calorie meal replacement dietary intervention.

OBJECTIVES: Shift work is associated with various health challenges, including obesity and metabolic disturbances. To address these concerns, a randomised controlled clinical trial was conducted to evaluate the efficacy of a low-calorie meal replacement (MR) dietary intervention for dinner among shift workers with obesity. This study focuses on the qualitative aspects of this intervention, aiming to explore the experiences and perceptions of shift workers who participated in the trial. DESIGN: Following the completion of the intervention, semi-structured face-to-face or telephone interviews were conducted with a purposive sample of trial participants. Data analysis was inductive, thematic using NVivo V.10 software. SETTING: The intervention was conducted among shift workers with obesity in a private hospital in Sri Lanka and resulted in a modest decrease in weight. PARTICIPANTS: Using purposeful maximum variation sampling, we recruited eight healthcare shift workers who took part in a weight loss intervention. RESULTS: All participants expressed satisfaction with the MR meal for dinner, highlighting its positive impact on their well-being. Despite initial difficulties, strong determination and motivation by results supported adherence. Some participants suggested that the MR could be improved with sweeter taste and more flavour options. Few reported mild bloating at the beginning, but no serious side effects were noted. Participants felt lighter in their bodies due to weight loss. The method's simplicity was the most frequently reported benefit, making it feasible even during busy night shifts. Overall, participants highly recommended the intervention to others in need. CONCLUSION: Participants experienced weight loss by replacing their dinner with the MR. This study offers valuable insights for tailoring future workplace-based dietary interventions for this vulnerable population. TRIAL REGISTRATION NUMBER: ACTRN12622000231741.

Shift Work is Associated with an Elevated White Blood Cell Count: A Systematic Review and Meta-Analysis.

The white blood cell (WBC) count increases significantly in reaction to infections and certain chronic diseases. Shift employment increases the risk for chronic low-grade inflammation and the progression of several chronic diseases. The objective of this study was to systematically evaluate the evidence from studies on total and differential WBC counts in shift employees. A literature search was performed in PubMed®, Web of Science, and Scopus databases using keywords for research published before March 1, 2022. A meta-analysis was conducted for total and differential WBC counts using a random-effects approach. A total of 25 studies covering a sample of 37,708 day and shift employees were included in this review. The studies represented America, Europe, East Asia, and Middle East. A significant increase in the total counts (×109/L) of WBC [mean difference (MD) = 0.43; 95% confidence interval (CI): 0.34-0.52; P < 0.001], lymphocytes (MD = 0.16; 95% CI: 0.02-0.30; P = 0.02), monocytes (MD = 0.04; 95% CI: 0-0.07; P = 0.03), and eosinophils (MD = 0.01; 95% CI: 0-0.01; P = 0.03) was observed in shift workers compared to the day counterparts. However, neutrophils and basophils were not significantly different between the groups. Shift work significantly increases the total and differential blood counts in peripheral circulation. Therefore, total and differential WBC counts represent a relatively inexpensive biomarker for diagnostics and prognostics of diseases in shift workers.

The efficacy of morning versus evening exercise for weight loss: A randomized controlled trial.

OBJECTIVE: The aim of this study was to investigate the influence of morning versus evening exercise on weight loss, cardiometabolic health, and components of energy balance. METHODS: A total of 100 inactive adults with overweight or obesity were randomized to morning exercise (AMEx; 06:00-09:00), evening exercise (PMEx; 16:00-19:00), or wait-list control (CON). AMEx and PMEx were prescribed 250 min·wk-1 of self-paced aerobic exercise for 12 weeks. Anthropometry and body composition, physical activity, and dietary intake were assessed at baseline, 6 weeks, and 12 weeks. Cardiorespiratory fitness (V̇O2 peak), resting metabolic rate, and blood markers were assessed at baseline and 12 weeks. Body composition and V̇O2 peak were also measured at 3- and 6-month follow-up. RESULTS: AMEx and PMEx lost weight during the intervention (mean [SD], AMEx, -2.7 [2.5] kg, p < 0.001; PMEx, -3.1 [3.4] kg, p < 0.001). V̇O2 peak significantly increased in both intervention groups, and these changes were different from CON (AMEx, +4.7 mL·kg-1 ·min-1 , p = 0.034; PMEx, +4.2 mL·kg-1 ·min-1 , p = 0.045). There were no between-group differences for resting metabolic rate or physical activity. At 12 weeks, total energy intake was significantly reduced in both AMEx and PMEx versus CON (AMEx, -3974 kJ, p < 0.001; PMEx, -3165 kJ, p = 0.001). CONCLUSIONS: Adults with overweight and obesity experience modest weight loss in response to an exercise program, but there does not appear to be an optimal time to exercise.

Body composition and appetite: fat-free mass (but not fat mass or BMI) is positively associated with self-determined meal size and daily energy intake in humans.

The idea of body weight regulation implies that a biological mechanism exerts control over energy expenditure and food intake. This is a central tenet of energy homeostasis. However, the source and identity of the controlling mechanism have not been identified, although it is often presumed to be some long-acting signal related to body fat, such as leptin. Using a comprehensive experimental platform, we have investigated the relationship between biological and behavioural variables in two separate studies over a 12-week intervention period in obese adults (total n 92). All variables have been measured objectively and with a similar degree of scientific control and precision, including anthropometric factors, body composition, RMR and accumulative energy consumed at individual meals across the whole day. Results showed that meal size and daily energy intake (EI) were significantly correlated with fat-free mass (FFM, P values < 0·02-0·05) but not with fat mass (FM) or BMI (P values 0·11-0·45) (study 1, n 58). In study 2 (n 34), FFM (but not FM or BMI) predicted meal size and daily EI under two distinct dietary conditions (high-fat and low-fat). These data appear to indicate that, under these circumstances, some signal associated with lean mass (but not FM) exerts a determining effect over self-selected food consumption. This signal may be postulated to interact with a separate class of signals generated by FM. This finding may have implications for investigations of the molecular control of food intake and body weight and for the management of obesity.

Shiftwork and the Risk of Metabolic Syndrome Among Health Care Workers: A Comparative Cross-Sectional Study.

OBJECTIVE: This study evaluated the association between shiftwork and metabolic syndrome (MetS) among a group of health care workers in Sri Lanka. METHODS: This study was in comparative cross-sectional design with 78 shiftworkers and nonshiftworkers 18 years and older. Data were collected through questionnaires, anthropometric measures, and blood tests. Metabolic syndrome was diagnosed based on the International Diabetes Federation and modified National Cholesterol Education Program, Adult Treatment Panel III criteria. RESULTS: The prevalence of MetS according to the International Diabetes Federation criteria was 16.2% and 36.6% among day workers and shiftworkers ( P = 0.043). According to modified National Cholesterol Education Program, Adult Treatment Panel III, 18.9% of day workers and 36.6% of shiftworkers had MetS ( P = 0.083). The best predictors of MetS were age (odds ratio, 1.07; 95% confidence interval, 1.02-1.12; P = 0.008) and shiftwork (odds ratio, 2.78; confidence interval, 0.90-8.72; P = 0.076). CONCLUSION: Shiftworkers had a more than twofold increased risk of developing MetS than day workers. Intervention targeting diet, physical activity, awareness sessions, and health screenings should be promoted.

Shift work and the risk for metabolic syndrome among healthcare workers: A systematic review and meta-analysis.

Shift work, defined as work occurring outside typical daytime working hours, is associated with an increased risk for metabolic syndrome (MetS) due to several biological and environmental changes. The MetS refers to the clustering of several known cardiovascular risk factors, including insulin resistance, obesity, dyslipidemia, and hypertension. This systematic review aims to evaluate the literature on the association between shift work and the risk of MetS in employees of the health sector. A systematic search was conducted in PubMed, Web of Science, and Scopus databases using appropriate keywords for studies published before September 1, 2021. Eligible studies were those that compared the prevalence of MetS between day and shift healthcare workers; had a cross-sectional, case-control, or cohort study design; provided sufficient data for calculating odds ratios or relative risks with 95% confidence intervals; and articles in English. The Joanna Briggs Institute prevalence critical appraisal tool was used for quality analysis. Risk for MetS and related measures of effect size were retrieved from studies for meta-analysis. Twelve studies met the criteria for inclusion in the review and meta-analysis. Sample sizes ranged from 42 to 738, and the age range of subjects was between 18 and 65 years. Ten studies demonstrated high methodological quality, while two studies were of average quality. Ten out of 12 studies in the review demonstrated a higher risk in shift workers for developing MetS than day workers. The pooled OR of MetS in shift workers based on 12 studies was 2.17 (95% CI = 1.31-3.60, P = 0.003; I2  = 82%, P < 0.001). Shift workers exhibited more than a twofold increase in the chance of developing MetS in comparison with day workers.