The association between obesity severity and food reward in adolescents with obesity: a one-stage individual participant data meta-analysis.

BACKGROUND: Food reward and cue reactivity have been linked prospectively to problematic eating behaviours and excess weight gain in adults and children. However, evidence to date in support of an association between degree of adiposity and food reward is tenuous. A non-linear relationship between reward sensitivity and obesity degree has been previously proposed, suggesting a peak is reached in mild obesity and decreases in more severe obesity in a quadratic fashion. OBJECTIVE: To investigate and characterise in detail the relationship between obesity severity, body composition, and explicit and implicit food reward in adolescents with obesity. METHODS: Data from seven clinical trials in adolescents with obesity were aggregated and analysed in an independent participant data meta-analysis. Linear and curvilinear relationships between the degree of obesity and explicit and implicit reward for sweet and high fat foods were tested in fasted and fed states with BMI-z score as a continuous and discrete predictor using clinically recognised partitions. RESULTS: Although positive associations between obesity severity and preference for high-fat (i.e. energy dense) foods were observed when fasted, none reached significance in either analysis. Conversely, adiposity was reliably associated with lower reward for sweet, particularly when measured as implicit wanting (p = 0.012, ηp2 = 0.06), independent of metabolic state. However, this significant association was only observed in the linear model. Fat distribution was consistently associated with explicit and implicit preference for high-fat foods. CONCLUSIONS: A limited relationship was demonstrated between obesity severity and food reward in adolescents, although a lower preference for sweet could be a signal of severe obesity in a linear trend. Obesity is likely a heterogenous condition associated with multiple potential phenotypes, which metrics of body composition may help define. CLINICAL TRIAL REGISTRATIONS: NCT02925572: https://classic. CLINICALTRIALS: gov/ct2/show/NCT02925572 . NCT03807609: https://classic. CLINICALTRIALS: gov/ct2/show/NCT03807609 . NCT03742622: https://classic. CLINICALTRIALS: gov/ct2/show/NCT03742622 . NCT03967782: https://classic. CLINICALTRIALS: gov/ct2/show/NCT03967782 . NCT03968458: https://classic. CLINICALTRIALS: gov/ct2/show/NCT03968458 . NCT04739189: https://classic. CLINICALTRIALS: gov/ct2/show/NCT04739189 . NCT05365685: https://www. CLINICALTRIALS: gov/study/NCT05365685?tab=history .

The energy content of meals with a similar macronutrient distribution may have a greater impact on appetite sensations than food preferences in adolescents with obesity: A secondary analysis.

PURPOSE: The energy and macronutrient composition of a meal has been shown to influence postprandial appetitive responses, but it is not clear how energy content independent of macronutrient distribution affects postprandial appetite in adolescents with obesity. Extracting data from a primary study testing the effect of energy turnover on appetite, this secondary analysis assessed how fixed meals varying in energy content with similar macronutrient distributions influences postprandial appetite sensations and food reward. METHODS: Using a randomised, counterbalanced crossover design, N = 14 adolescents with obesity (Mage = 12.71, SDage = 0.99; 10 female) consumed fixed lunch meals with similar macronutrient content starting at 750 kcal in energy and progressively increasing by 250 kcal on three different test days. Liking and wanting for food images varying in fat and taste were assessed at baseline and immediately after meal consumption. Appetite sensations were assessed in half-hour intervals from baseline to 1-h post-meal. RESULTS: The area under the curve for subjective hunger (p < .001, ω = 0.36), desire to eat (p < .001, ω = 0.54), and prospective food consumption (p = .004, ω = 0.32) were significantly lower after consumption of the higher calorie meals relative to the lowest. Explicit wanting for sweet foods increased after intake of the intermediate calorie meal yet decreased after the highest calorie meal (p = .014, ω = 0.09). Conversely, implicit wanting sweet bias increased after consumption of the test meal independent of energy content (p < .001, ω = 0.15). CONCLUSION: The consumption of additional calories without a meaningful change in macronutrient distribution may affect appetite sensations more reliably than hedonic responses to energy-dense foods in adolescents with obesity.

The Effects of Statins on Cognitive Performance Are Mediated by Low-Density Lipoprotein, C-Reactive Protein, and Blood Glucose Concentrations.

Statins are widely used for cardiovascular disease prevention but their effects on cognition remain unclear. Statins reduce cholesterol concentration and have been suggested to provide both beneficial and detrimental effects. Our aim was to investigate the cross-sectional and longitudinal association between statin use and cognitive performance, and whether blood low-density lipoprotein, high-density lipoprotein, triglycerides, glucose, C-reactive protein, and vitamin D biomarkers mediated this association. We used participants from the UK biobank aged 40-69 without neurological and psychiatric disorders (n = 147 502 and n = 24 355, respectively). We performed linear regression to evaluate the association between statin use and cognitive performance and, mediation analysis to quantify the total, direct, indirect effects and the proportion meditated by blood biomarkers. Statin use was associated with lower cognitive performance at baseline (ß = -0.40 [-0.53, -0.28], p = <.0001), and this association was mediated by low-density lipoprotein (proportion mediated = 51.4%, p = .002), C-reactive protein (proportion mediated = -11%, p = .006) and blood glucose (proportion mediated = 2.6%, p = .018) concentrations. However, statin use was not associated with cognitive performance, measured 8 years later (ß = -0.003 [-0.11, 0.10], p = .96). Our findings suggest that statins are associated with lower short-term cognitive performance by lowering low-density lipoprotein and raising blood glucose concentrations, and better performance by lowering C-reactive protein concentrations. In contrast, statins have no effect on long-term cognition and remain beneficial in reducing cardiovascular risk factors.

Perceived stress is related to lower blood pressure in a Swedish cohort.

AIMS: General psychosocial stress and job strain have been related to blood pressure (BP) with conflicting results. This study sought to explore the contribution of several lifestyle factors in the relation between general psychosocial stress, job strain and BP. METHODS: This cross-sectional study investigated the association of general stress and job strain with systolic BP (SBP) and diastolic BP in a sample of 9441 employed individuals from the EpiHealth cohort. General stress was measured by the Perceived Stress Scale. Job strain was assessed with the Job Content Questionnaire, assessing two dimensions of job strain: psychological job demand and decision latitude. Linear regression and sensitivity analysis were performed. RESULTS: At the uncorrected model, general stress, job demand and decision latitude were all inversely associated with SBP. After further adjustment for lifestyle and health parameters, only general stress was associated with SPB (ß coefficient: -0.103; 95% confidence interval -0.182 to 0.023). CONCLUSIONS: General stress is associated with lower SBP independently of lifestyle in middle-aged adults. Our findings point towards a major contribution for job-unrelated stressors in determining SBP and support the pivotal role of lifestyle behaviours and health status in modulating the effect of stress on BP, calling for a careful selection of confounders.

Job satisfaction and job tenure of people with mental health disorders: a UK Biobank cohort study.

AIMS: Job satisfaction plays an important role for the life quality and health of working individuals. While studies have shown that self-reported mental health conditions such as stress, anxiety and depression are associated with job satisfaction, a large population-based study exploring and comparing self-reported physician posed diagnosed conditions and their association with job satisfaction and job tenure is missing. This study addresses the gap along with exploring the impact of the neurotic personality trait and other possible contributing factors. METHODS: Sixteen mental health disorders diagnosed by physicians, categorised into four major groups were investigated in relation to employment status (108,711 participants) and in relation to job satisfaction and job tenure (34,808 participants). Analyses were performed using linear regression adjusted for age, sex, townsend deprivation index, body mass index, education, physical activity, work hours and neuroticism. RESULTS: Neurotic and stress disorders, eating disorders and other mental health disorders were strongly associated with lower job satisfaction and shorter job tenure in both unadjusted and adjusted analyses. Neuroticism was strongly linked to job satisfaction but was not associated with job tenure. CONCLUSIONS: Study findings clarify the complex relationship of mental health with job satisfaction and job tenure, which is very important to understand in designing measures to improve working life participation of individuals with mental health issues.

The influence of personality on the risk of myocardial infarction in UK Biobank cohort.

Personality is a strong determinant for several health-related behaviours and has been linked to the development of cardiovascular diseases. However, the reports of personality's mediating role have been inconsistent with no data available from large population-based cohorts. The study aimed to create proxies for the Big Five personality traits, extraversion, agreeableness, conscientiousness, openness and neuroticism, to examine the longitudinal relationship between personality and myocardial infarction in the UK Biobank. The study sample comprised of 484,205 participants (55% female, 45% male, mean age 56.4 ± 8.1 years) from UK Biobank cohort with a mean follow-up of 7 years. The personality proxies sociability, warmth, diligence, curiosity and nervousness were created using self-reported data on psychological factors, mental health and social support, to match the facets of the Big Five traits. As neuroticism is the only Big Five personality trait available in the UK Biobank, it was included to validate the personality proxies. Myocardial infarction outcome information was collected from hospital records, death registries or was self-reported. Logistic regression and Cox proportional hazard regression were used to estimate odds ratio (OR) and hazard ratios (HR), respectively with 95% confidence intervals (CI) adjusted for demographics (age, sex, socioeconomic status, ethnicity), health-related factors (BMI, diabetes, systolic and diastolic blood pressure) and lifestyle factors (alcohol intake, smoking, and moderate-to-vigorous physical activity). Diligence was found to be significantly associated with lower prevalent myocardial infarction [OR: 0.87; (CI 0.84-0.89)] and lower incident myocardial infarction [HR: 0.88; (CI 0.85-0.92)]. Sociability was also protective against prevalent [OR: 0.89; (CI 0.87-0.92)] and incident [HR: 0.90; (CI 0.87-0.93)] myocardial infarction. Conversely, nervousness inferred a higher risk for both prevalent [OR: 1.10; (CI 1.08-1.12)] and incident [HR: 1.07; (CI 1.04-1.09)] myocardial infarction during follow-up. Sex-stratified analyses revealed that nervousness significantly increases the risk for incident myocardial infarction among women [HR: 1.13; (CI 1.08-1.19)] compared to men [HR: 1.05; (CI 1.02-1.08)]. By using our created proxies, we were able to investigate the impact of personality on the development of myocardial infarction. Persons with higher levels of diligence and sociability mimicking predominantly conscientiousness and extraversion personalities respectively are less likely to experience myocardial infarction, while personalities predominantly characterised by nervousness pose higher risk for developing myocardial infarction. These initial findings invite further validation of the use of the personality proxies in UK Biobank cohort.

Bone Response to High-Intensity Interval Training versus Moderate-Intensity Continuous Training in Adolescents with Obesity.

INTRODUCTION: Since adolescents with obesity are prone to bone fragility during weight loss, the aim was to compare the impact of high-intensity interval training (HIIT) versus moderate-intensity continuous training (MICT) on bone density, geometry, and strength. METHODS: Sixty-one adolescents were randomly assigned to 2 cycling trainings (HIIT and MICT) and a control (CTR, without training) group. Anthropometry, dual-energy X-ray absorptiometry with hip structural analysis and the trabecular bone score (TBS) were assessed before and after the 16-week intervention. RESULTS: Body mass index (BMI) and fat mass (FM) percentage decreased at T1 versus T0 in both training groups (p < 0.001 for HIIT, p = 0.01 for MICT), though to a larger extent in HIIT (p < 0.05). Total body bone mineral density (BMD) and bone mineral content (BMC) increased in both training groups (p < 0.001), but to a greater extent in HIIT for BMC (p < 0.05). Lumbar spine BMD and BMC increased in both training groups (p < 0.001 for HIIT, p < 0.01 for MICT), with a time × group interaction between HIIT and CTR (p < 0.05) only. TBS increased in both training groups (p < 0.01 for HIIT, p < 0.05 for MICT). Hip BMD and BMC increased in both HIIT (p < 0.001 and p < 0.01) and MICT (p < 0.01 and p < 0.05). At the narrow neck (NN), endocortical diameter, width (p < 0.01), cross-sectional moment of inertia, and section modulus (Z) (p < 0.05) increased only in the HIIT group, such as BMD and Z (p < 0.05) at the intertrochanteric region (IT) and average cortical thickness (p < 0.001) and width (p < 0.05) at the femoral shaft. At the NN and IT, the buckling ratio decreased only in the HIIT group (p < 0.05), predicting higher resistance to fracture. CONCLUSIONS: In addition to inducing greater BMI and FM percentage decreases in comparison to MICT, HIIT improves multisite bone density, geometry, and strength, which heighten the justification for HIIT as part of weight loss interventions in adolescents with obesity.

Major sex differences in migraine prevalence among occupational categories: a cross-sectional study using UK Biobank.

BACKGROUND: Migraine represents one of the most prevalent neurological conditions worldwide. It is a disabling condition with high impact on the working situation of migraineurs. Interestingly, gender-related differences regarding an association of migraine with important occupational characteristics has been hardly studied. METHODS: The current study scrutinizes gender-specific differences in the prevalence of migraine across a broad spectrum of occupational categories, shedding also light on associations with important job-related features such as shift work, job satisfaction, and physical activity. The study included data from 415 712 participants from the UK Biobank cohort, using the official ICD10 diagnosis of migraine and other health conditions as selection criteria. Prevalence ratios of migraineurs compared to healthy controls among different occupational categories and job-related variables were estimated using log-binomial regression analyses. Statistical models were adjusted for important sociodemographic features such as age, BMI, ethnicity, education and neuroticism. To better highlight specific differences between men and women we stratified by sex. RESULTS: We detected a differential prevalence pattern of migraine in relation to different job categories between men and women. Especially in men, migraine appears to be more prevalent in highly physically demanding occupations (PR 1.38, 95% CI [0.93, 2.04]). Furthermore, migraine is also more prevalent in jobs that frequently involve shift or night shift work compared to healthy controls. Interestingly, this prevalence is especially high in women (shift work PR 1.45, 95% CI [1.14, 1.83], night shift work PR 1.46, 95% CI [0.93, 2.31]). CONCLUSION: Our results show that migraine is genderdependently associated with physically demanding jobs and shift working.

Time spent outdoors and risk of myocardial infarction and stroke in middle and old aged adults: Results from the UK Biobank prospective cohort.

BACKGROUND: Time spent outdoors has been previously related to several cardiovascular risk factors, implying that it may confer either beneficial or harmful effects on cardiovascular health. However, no large population-based studies have examined the relation between time spent outdoors and myocardial infarction and stroke. OBJECTIVES: We aimed to investigate the longitudinal relation between time spent outdoors and myocardial infarction and stroke in large UK population-based cohort. METHODS: A total of 446,648 participants from UK Biobank were included in the study of which 431,146 participants (56% females and 44% males with a mean age of 56.4 ± 8.1 years) were followed for a median time of 7 years. Time spent outdoors was self-reported and participants were stratified into quantiles (less than 1.5 [reference group]; 1.5 to 2.4; 2.5 to 3.5 and more than 3.5 h per day outdoors). Myocardial infarction and stroke events were either collected from hospital records and death registries or were self-reported by the participants. Cox proportional hazard regression was used for the analysis. In addition to age and sex, analyses were adjusted for potential demographic (TDI, ethnic background, current employment status), lifestyle (alcohol intake frequency, current tobacco use, sedentary time and moderate-to-vigorous physical activity), health related factors (BMI, systolic and diastolic blood pressure) and environmental indicators (NO2, NOx, PM10, PM2.5-10, PM2,5, noise pollution, % greenspace, % natural environment and % water). RESULTS: A 20% increased risk for myocardial infarction incidence was observed among participants who reported spending more than 3.5 h/day outdoors (HR: 1.20, 95% CI: 1.06-1.36) compared to the reference group. A trend was also observed for stroke (HR: 1.14, 95% CI: 0.97-1.34). CONCLUSION: Findings from the present study indicate that spending more than 3.5 h/day outdoors is a risk factor for myocardial infarction and stroke. Future research is needed to further understand the relation between time spent outdoors and cardiovascular disease.

Comparing the Effects of Immersed Versus Land-Based High-Intensity Interval Cycling on Energy Intake, Appetite Sensations and Perceived Exertion Among Healthy Men.

Immersed exercise has been shown to induce higher energy expenditure and no difference or increase in food intake compared with similar exercise on land. In this study, we compared the effects of acute high-intensity cycling performed on land versus when immersed on subsequent energy intake (EI), appetite sensations and perceived exertion (RPE) in healthy men. Ten participants in a postprandial condition completed three experimental visits in a randomized order: a control condition (CONT); a high-intensity interval cycling exercise performed on land (HIIE-L) and the same exercise while immersed in water (HIIE-A) with a similar targeted heart rate. We observed no difference in energy and macronutrient intake and in area under the curve (AUC) for appetite sensations between sessions. The RPE at the end of HIIE-L was negatively correlated with EI (r=-0.67; p < 0.05), AUC for hunger (r=-0.86, p < 0.01), desire to eat (r=-0.78, p < 0.05) and prospective food consumption (r=-0.86, p < 0.01). Conversely, the RPE at the end of HIIE-L was positively correlated with AUC for fullness (r = 0.76, p < 0.05). No such correlations were observed for HIIE-A. The present study was the first to observe that immersion did not influence EI after HIIE cycling, but immersion blunted the relationship between session RPE and subsequent energy intake and appetite sensations relative to HIIE on land.

Appetite Control Might not Be Improved after Weight Loss in Adolescents with Obesity, Despite Non-Persistent Metabolic Syndrome.

The aim of this study was to evaluate the effect of a multidisciplinary weight loss intervention on energy intake and appetite sensations in adolescents with obesity, depending on the initial diagnosis or persistence of the metabolic syndrome. Ninety-two adolescents with obesity (12-15 years) followed a 16-week multidisciplinary weight loss intervention. Anthropometric and body composition characteristics, metabolic profile, ad libitum daily energy intake, and appetite sensations were assessed before and after the intervention. The presence of metabolic syndrome (MS) was determined at baseline (MS vs. non-MS) and after the program (persistent vs. non-persistent). While the intervention was effective in inducing weight loss (body weight T0: 87.1 ± 14.9 vs. T1: 81.2 ± 13.0 kg; p < 0.001) and body composition improvements in both adolescents with and without MS, energy intake (p = 0.07), hunger (p = 0.008), and prospective food consumption (p = 0.03) increased, while fullness decreased (p = 0.04) in both groups. Energy intake and appetite were not improved in non-persistent MS after the program and remained significantly higher among non-persistent adolescents compared with initially non-MS adolescents. To conclude, appetite control seems impaired in obese adolescents, irrespective of being affected by MS or not, whereas the treatment of MS in this population might fail to effectively preclude the adolescents from potential post-intervention compensatory food intake and subsequent weight regain.

Psycho-Physiological Responses to a 4-Month High-Intensity Interval Training-Centered Multidisciplinary Weight-Loss Intervention in Adolescents with Obesity.

BACKGROUND: To evaluate the impact of 4 months of a high-intensity interval training (HIIT)-centered weightmanagement intervention on health-related quality of life (HR-QOL), health perception (HP) and physical selfperception (PSP) in adolescents with obesity. METHODS: Fifty-six adolescents with obesity (28 girls; mean body mass index [BMI], 35±4.89 kg/m2; z-BMI, 2.3±0.3; 11-17 years) followed a multidisciplinary weight-management intervention composed of nutritional counseling, HIIT program, and health-related therapeutic education. Anthropometric parameters, body composition (dual X-ray absorptiometry), and maximal aerobic capacities (maximal oxygen consumption [VO2peak]) were assessed, and self-reported questionnaires were used to assess HR-QOL (36-item short form survey), HP and PSP at baseline (T0) and post-intervention (T1). RESULTS: Body weight (92.6±18.9 to 85.9±16.2 kg), BMI (35.0±4.8 to 32.1±4.5 kg/m2), z-BMI (2.3±0.3 to 2.1±0.3) and fat mass percentage (36.0%±9.1% to 30.4%±7.8%) were significantly decreased (P<0.001) between T0 and T1. There was a tendency for VO2peak to increase from 26.35±5.81 mL/kg/min at T0 to 28.79±6.59 mL/kg/min at T1 (P=0.06). Physical functioning (P=0.002), physical limitation (P=0.048), general health (P<0.001) and bodily pain (P=0.030) were improved at T1. A significant improvement occurred in dimensions of HP such as physical condition (P=0.001), adiposity (P<0.001), alimentation (P<0.001), general health (P=0.038), and perceived general health (P=0.001). In addition, there was an improvement in items of PSP such as self-perceived coordination (P=0.022), endurance (P=0.001) and activity (P=0.001), global self-concept (P=0.015), and appearance (P=0.016). Physical but not mental HR-QOL domains, HP and PSP were associated with weight reduction. CONCLUSION: While HIIT favors improved HR-QOL, HP status and PSP in adolescents with obesity, physical but not mental HR-QOL, HP and PSP were associated with weight reduction.

Eccentric Cycling Training Improves Health-Related Quality of Life in Adolescents with Obesity.

INTRODUCTION: While eccentric (ECC) training appears to be more efficient than concentric (CON) training at improving body composition in adolescent with obesity, its impact on health-related quality of life (HRQOL) has never been studied. OBJECTIVE: The aim of this study is to compare the effects of 2 cycling training modalities, i.e., ECC vs. CON, in adolescents with obesity on HRQOL and health perception (HP). METHODS: A total of 24 adolescents with obesity, aged 12-16 years, were randomized to either a 12-week ECC or a CON cycling training program performed at the same oxygen consumption (VO2). Anthropometric measurements, body composition, maximal incremental tests, HRQOL (Vécu et Santé Percue de l'Adolescent [VSP-A], Medical Outcome Study Short Form [SF-36]), and HP were assessed at before and after training. RESULTS AND CONCLUSION: Both CON and ECC cycling trainings promoted significant improvements in BMI, VO2peak, total fat mass, and fat-free mass, with better improvements in body composition parameters in the ECC group (p < 0.05). The VSP-A total score increased after CON (p < 0.01) and ECC (p < 0.001) training, with better enhancement for the ECC group (p < 0.05). The SF-36 physical score increased after both CON (p < 0.01) and ECC (p < 0.001) trainings. The global HP score increased only after ECC training (p < 0.001). Except for the energy-vitality item, no significant correlation was found between changes in HRQOL and its subdomains and anthropometric, body composition, and functional parameters. Both ECC and CON cycling trainings are associated with positive changes in HRQOL and HP. However, ECC seems to induce greater improvements in HRQL and HP than CON cycling training, which is probably not due to the anthropometric, body composition, and functional changes.

Important Difference between Occupational Hazard Exposure among Shift Workers and Other Workers; Comparing Workplace before and after 1980.

Improving health and safety at work has been an important issue for the European Union since the 1980s. The existing literature supports that shift work is associated with multiple indicators of poor health but frequently neglects the potential impact of occupational hazards. This study aims at describing and comparing the exposure to different workplace hazards among shift and other workers before and after 1980. Exposure to different workplace hazards (noise, dust, pollutant, and other physical stressors) were analyzed among 119,413 participants from the UK Biobank cohort. After stratifying the analyses before and after 1980, exposure was compared between shift and other workers. Potential confounding variables (sex, age, ethnicity, education level, occupational category, and neuroticism) were adjusted for in the log-binomial regression. Shift workers had a higher prevalence ratio (PR) than other workers of being exposed to almost all identified hazards both before or after 1980. They were also more likely to be exposed to multiple hazards compared to other workers, both before 1980 (PR: 1.25; 95% CI: 1.21-1.30) and after 1980 (PR: 1.34; 95% CI: 1.30-1.38). The prevalence of all measured risk factors was higher after 1980 than before 1980 among shift workers. Of note, the work environment has improved overall for other workers. Our findings suggest that changes at the workplace have benefited other workers more than shift workers as they are still more exposed to all occupational hazards.

Bone response to eccentric versus concentric cycling in adolescents with obesity.

OBJECTIVES: Because adolescents with obesity are susceptible to bone fragility during weight loss (WL), we evaluated the impact of eccentric (ECC) versus classical concentric (CON) training at the same oxygen consumption (V˙O2) on bone density, geometry and strength. METHODS: Thirty five adolescents were included into 2 training (CON and ECC cycling) and a control (CTR, without training) groups. Anthropometry, dual-energy X-ray absorptiometry, hip structural analysis and quantitative bone ultrasound were assessed before and after the 12-week intervention. RESULTS: The trainings promoted significant improvements in body mass index, total fat (FM) and lean mass (LM), with better improvements for FM and LM in the ECC group (p < 0.05). Leg LM percentage increased only in the ECC group (p < 0.05). Total body bone mineral content and density increased in both training groups (p < 0.001) with significant time x group interactions only between ECC and CTR (p < 0.05). Buckling ratio at the intertrochanteric region and femoral shaft increased only in CTR and CON groups (p < 0.05). Speeds of sounds at the calcaneum increased only in ECC group (p < 0.01). CONCLUSIONS: Bone fragility, from a compromised relationship between density, geometry and strength, might be prevented with the ECC modality.

Does exercising before or after a meal affect energy balance in adolescents with obesity?

BACKGROUND AND AIM: Exercise timing has been suggested to affect appetite and energy intake (EI). The aim of this study was to examine the impact of exercising immediately before or after a meal on EI, appetite sensations and food reward (FR) in adolescents with obesity. METHODS AND RESULTS: Seventeen adolescents with obesity completed 3 experimental sessions (randomized controlled trial): rest + lunch (CON); exercise + lunch (EX-MEAL); lunch + exercise (MEAL-EX). The exercise consisted of cycling 30 min at 65%V̇O2peak. Outcomes included ad libitum EI (weighed lunch and dinner), FR (Leeds Food Preference Questionnaire at pre- and post-combination of exercise/rest and lunch, and pre-dinner) and appetite sensations (visual analogue scales). EI was not different between conditions. Compared with CON, relative EI at lunch was lower in EX-MEAL and MEAL-EX (p ≤ 0.05) and daily only in MEAL-EX (p < 0.01). Postprandial fullness was higher in EX-MEAL compared to CON. Compared with CON, both EX-MEAL and MEAL-EX attenuated the increase in wanting for sweet food and reduced explicit liking for fat. CONCLUSIONS: These preliminary results suggest that exercising immediately before or after a meal produce few differences in appetite and have small beneficial effects on overall energy balance in adolescents with obesity, as well as on FR. CLINICAL TRIALS: NCT03967782.

Effect of a 10-month residential multidisciplinary weight loss intervention on food reward in adolescents with obesity.

BACKGROUND: While multidisciplinary weight loss (WL) programs have been suggested to improve the sensitivity of appetite control system, this study examined for the first time the effect of a specific multidisciplinary intervention on the hedonic aspects of food intake in adolescents with obesity. STUDY DESIGN: Twenty-four adolescents (11-15 years) with obesity (mean BMI: 35.7 ±â€¯4.5 kg/m2; BMI percentile: 98.7 ±â€¯0.5) took part in a 10-month inpatient WL program, which included physical activity, nutritional education and psychological support. Height, weight, body composition, food reward (pre- and post-meal), ad libitum energy intake, appetite sensations and eating behavior traits were assessed at baseline, 5 months and at the end of the 10-month intervention. Analyses were conducted with linear mixed models and paired t-tests. RESULTS: The mean WL was 8.9 ±â€¯6.9 kg. Appetite sensations and pre-meal hedonic ratings of liking for all food categories (HF: high-fat; LF: low-fat; SA: savory; SW: sweet) increased after 5 months (fasting hunger, p = 0.02; fasting desire to eat, p = 0.01; daily hunger, p = 0.001; pre-meal liking for HFSA, p = 0.03; LFSA, p = 0.04; HFSW, p = 0.009; LFSW, p = 0.005). In contrast, appetite sensations (fasting and daily), emotional eating (p < 0.001), uncontrolled eating (p = 0.009), and pre-meal explicit liking (for all food categories) decreased between months 5 and 10. Post-meal liking for HFSA (p < 0.001), LFSA (p = 0.002), HFSW (p = 0.02) and LFSW (p < 0.001) decreased between baseline and month 5 and remained unchanged between months 5 and 10. CONCLUSION: These findings suggest that adaptive mechanisms to WL occurring in the short-to-medium term are attenuated in the longer term with the persistence of WL. These results indicate improvements in the reward response to food in adolescents with obesity and may contribute to the beneficial effect of multicomponent WL interventions in this population. Future studies are required to confirm these findings and elucidate underlying mechanisms.

Delayed meal timing after exercise is associated with reduced appetite and energy intake in adolescents with obesity.

BACKGROUND: While the beneficial effects of exercise on appetite might depend on its timing during the day or relative to a meal, this remains poorly explored in youth. OBJECTIVES: To examine the importance of meal timing (+30 vs +90 minutes) after performing exercise on energy intake, appetite and food reward in adolescents with obesity. METHODS: Eighteen adolescents with obesity randomly completed three conditions: (a) lunch (12:00 pm) set 30 minutes after a rest session (11:00 am); (b) lunch (12:00 pm) set 30 minutes after an exercise session (11:00 am)(MEAL-30); (c) lunch (01:00 pm) set 90 minutes after an exercise session (11:00 am)(MEAL-90). Lunch and dinner ad libitum energy intake was assessed, food reward (LFPQ) assessed before and after lunch, and before dinner, appetite sensations were assessed at regular intervals. RESULTS: Energy intake was lower at MEAL-90 than MEAL-30 and CON at lunch (P < .05 and P < .01, respectively) and lunch + dinner combined (P < .001). A decrease in intake (g) of protein, fat and carbohydrate was observed. Post-exercise hunger was lower on MEAL-90 compared with CON. No condition effects were found at lunch for food reward. CONCLUSIONS: Delaying the timing of the meal after exercise might help affect energy balance by decreasing ad libitum energy intake without increasing hunger and by improving satiety in adolescents with obesity.

Is the SPARTACUS 15-15 test an accurate proxy for the assessment and tracking of maximal aerobic capacities in adolescents with obesity?

[Purpose] While there is a need for reliable field tests for the evaluation of physical fitness in pediatric obesity, the present work i) evaluates the validity of the Spartacus 15-15 test in indirectly assessing maximal aerobic capacity in adolescents with obesity and ii) evaluates its sensibility to weight loss. [Participants and Methods] Fifty-five 11-16 year-old adolescents with obesity (Tanner 3-4) were enrolled in a 12-week weight-management intervention. Maximal Aerobic fitness (VO2peak test + Spartacus test) and body composition (Dual X-ray absorptiometry) were assessed at baseline and after 12 weeks. [Results] Moderate correlations were found at baseline between VO2peak (2,231.90 ± 465.6 mL/min) and Spartacus stage (6.83 ± 1.8 stage, r=0.52; p≤0.05), speed (12.85 ± 1.8 km/h, r=0.52 ; p≤0.05) and time (20.6 ± 5.4 min; r=0.50; p≤0.05). The intervention favored significant improvements for VO2peak, Spartacus Rate of Perceived Exertion final stage, maximal speed and time. Change over time in VO2peak and Spartacus variables were not correlated. [Conclusion] The Spartacus test can be used as a proxy for VO2peak at baseline and can be used to estimate VO2peak using the proposed equation. The Spartacus 15-15 test might be a better indicator for changes in functional capacity than an indicator of VO2peak changes in youth with obesity.