Associations between sleep duration, sedentary time, physical activity, and health indicators among Canadian children and youth using compositional analyses

The purpose of this study was to examine the relationships between movement behaviours (sleep duration, sedentary time, physical activity) and health indicators in a representative sample of children and youth using compositional analyses. Cross-sectional findings are based on 4169 children and youth (aged 6–17 years) from cycles 1 to 3 of the Canadian Health Measures Survey. Sedentary time (SB), light-intensity physical activity (LPA), and moderate- to vigorous-intensity physical activity (MVPA) were accelerometer-derived. Sleep duration was subjectively measured. Body mass index z scores, waist circumference, blood pressure, behavioural strengths and difficulties, and aerobic fitness were measured in the full sample. Triglycerides, high-density lipoprotein-cholesterol, C-reactive protein, and insulin were measured in a fasting subsample. The composition of movement behaviours was entered into linear regression models via an isometric log ratio transformation and was found to be associated with all health indicators (p &lt; 0.01). Relative to other movement behaviours, time spent in SB or LPA was positively associated (p &lt; 0.04) and time spent in MVPA or sleep was negatively associated (p &lt; 0.02) with obesity risk markers. Similarly, LPA was positively associated (p &lt; 0.005) and sleep was negatively associated (p &lt; 0.03) with unfavourable behavioural strengths and difficulties scores and systolic blood pressure. Relative to other movement behaviours, time spent in SB was negatively associated (p &lt; 0.001) and time spent in MVPA (p &lt; 0.001) was positively associated with aerobic fitness. Likewise, MVPA was also negatively associated with several cardiometabolic risk markers (p &lt; 0.008). Compositional data analyses provide novel insights into collective health implications of 24-h movement behaviours and can facilitate interesting avenues for future investigations. </jats:p

Compositional analyses of the associations between sedentary time, different intensities of physical activity, and cardiometabolic biomarkers among children and youth from the United States

Introduction : Compositional data analysis is one appropriate method for co-dependent data, even when data are collected for a subdivision of the 24-hour period, such as the waking day. Objectives were to use compositional analyses to examine the combined and relative associations of sedentary time (ST), light-intensity physical activity (LPA), moderate-intensity physical activity (MPA), and vigorous-intensity physical activity (VPA) with cardiometabolic biomarkers in a representative sample of children and youth. Methods : This cross-sectional study included 2544 participants aged 6-17 years from the 2003-2006 United States National Health and Nutrition Examination Survey. ST (= 7 METs) were accelerometer-derived. Cardiometabolic biomarkers included waist circumference, body mass index (BMI) z-score, HDL-cholesterol, C-reactive protein, and blood pressure. Triglycerides, glucose, insulin, and LDL-cholesterol were measured in a fasting sub-sample of adolescents (n = 670). Compositional linear regression models were conducted. Results : The composition of ST, LPA, MPA, and VPA was significantly associated with BMI z-score, log waist circumference, systolic and diastolic blood pressure, HDL-cholesterol, and log plasma glucose (variance explained: 1-29%). Relative to the other three behaviors, VPA was negatively associated with BMI z-score (gamma VPA = -0.206, p = 0.005) and waist circumference (gamma VPA = -0.03, p = 0.001). Conversely, ST was positively associated with waist circumference (gamma ST = 0.029, p = 0.013). ST and VPA were also positively associated with diastolic blood pressure (gamma ST = 2.700, p = 0.018; gamma VPA = 1.246, p = 0.038), relative to the other behaviors, whereas negative associations were observed for LPA (gamma LPA = -2.892, p = 0.026). Finally, VPA was positively associated with HDL-cholesterol, relative to other behaviors (gamma VPA = 0.058, p<0.001). Conclusions : The ST and physical activity composition appears important for many aspects of cardiometabolic health in children and youth. Compositions with more time in higher-intensity activities may be better for some aspects of cardiometabolic health

Eating behavior traits and sleep as determinants of weight loss in overweight and obese adults

Objective: To examine the associations between eating behavior traits and weight loss according to sleep quality and duration in adults enrolled in common weight-loss interventions. Methods: Participants included overweight and obese men and women (n=150) (mean±s.d. age, 38.8±8.6 years; mean±s.d. body mass index (BMI), 33.3±3.5 kg m−2) who were subjected to a dietary intervention over a period of 12–16 weeks. Anthropometric measurements, eating behavior traits (Three-Factor Eating Questionnaire), sleep quality (total Pittsburgh Sleep Quality Index (PSQI) score) and sleep duration (hours per night, self-reported from the PSQI) were assessed at both baseline and post intervention. Linear regression analysis was used to quantify the relationships between eating behavior traits and changes in anthropometric markers for all subjects and by sleep categories (short sleep: <7 h per night vs recommended sleep: greater than or equal to7 h per night; poor sleep quality: greater than or equal to5 PSQI score vs good sleep quality: <5 PSQI score). We adjusted for age, sex and baseline BMI in analyses. Results: Baseline eating behavior traits were modest predictors of weight-loss success, but they were all significantly associated with their changes over the weight-loss intervention (P<0.01). The diet intervention induced significant changes in eating behavior traits and even more for those having a non-favorable eating behavior profile at baseline. We observed that changes in flexible control and strategic dieting behavior were constantly negatively associated with changes in body weight and fat mass (P<0.05) for recommended duration sleepers. The change in situational susceptibility to disinhibition was positively associated with the change in fat mass and body weight for those having healthy sleeping habits (P<0.05). For poor quality sleepers, the change in avoidance of fattening foods was negatively associated with changes in adiposity (P<0.05). Conclusion: Eating behavior traits and sleep may act together to influence the outcome of weight-loss programs

Physical Activity Plays an Important Role in Body Weight Regulation

Emerging literature highlights the need to incorporate physical activity into every strategy intended to prevent weight gain as well as to maintain weight loss over time. Furthermore, physical activity should be part of any plan to lose weight. The stimulus of exercise provides valuable metabolic adaptations that improve energy and macronutrient balance regulation. A tight coupling between energy intake and energy expenditure has been documented at high levels of physical exercise, suggesting that exercise may improve appetite control. The regular practice of physical activity has also been reported to reduce the risk of stress-induced weight gain. A more personalized approach is recommended when planning exercise programs in a clinical weight loss setting in order to limit the compensatory changes associated to exercise-induced weight loss. With modern environment promoting overeating and sedentary behavior, there is an urgent need for a concerted action including legislative measures to promote healthy active living in order to curb the current epidemic of chronic diseases

Sex differences in effects of mental work and moderate-intensity physical activity on energy intake in young adults

The aim of this study was to examine the acute effects of mental work and moderate-intensity physical activity on various components of energy balance in young and healthy adults. With the use of a randomized crossover design, 35 participants aged 24 ± 3 years completed three 45-min conditions, namely, (i) resting in a sitting position (control), (ii) reading and writing (mental work (MW)), and (iii) exercising on a treadmill at 40% of peak oxygen uptake (exercise), followed by an ad libitum lunch. The endpoints were spontaneous energy intake (EI), energy expenditure (EE), appetite sensations, and EI for the remainder of the day. We observed that the energy cost of the control and MW conditions was about the same whereas the exercise condition increased EE to a greater extent in men than women. Exercise induced a decrease in EI relative to EE compared to the control condition that was more pronounced in men than women. However, women tended to increase their energy intake after the MW condition compared to the control one whereas an opposite trend was observed in men. None of the appetite sensation markers differed significantly between both sexes. In conclusion, men and women have specific food intake patterns when submitted to cognitive and physical stimuli