Introduction In France March 14, 2020 a national lockdown was imposed in France for 55 days to prevent the spread of the Covid-19 and all schools were closed. This study aimed to investigate the effects of home confinement as a result of  lockdown on the activity (physical activity and sedentary behaviors), and their determinants, on French children (6-10 years) and adolescents (11-17 years). Methods The National Observatory for Physical Activity and Sedentary behaviors launched an online survey from April 1 st , to May 6 th , 2020 using popular social networks and websites. It compared the level of physical activity (PA), sitting and screen time before and during the lockdown and identified the impact of the initial PA (active vs. inactive), sedentary (high vs. low) profiles of the participants and the housing conditions. Results 6,491 children were included in this study. Initially active children and adolescents decreased their PA more than those initially inactive (p>0.001), while those who met the sitting time recommendations increased more their sitting time during lockdown (p<0.001). The same applies to screen time (p<0.001). Live in urban was associated with a decrease of PA (p<0.001), an increase of their sitting time (p<0.001) and children's screen time (p=0.002) during lockdown. Conclusion This study showed the deleterious effects of confinement caused by lockdown on physical activity and sedentary behaviors. Housing conditions were associated with lifestyle behaviors over this period of lockdown. Future public health policies should consider these results.

The aim of the present study was to evaluate whether the COVID-19-related confinement and social restrictions affected the levels of physical fitness and academic achievement in primary school French children. A total of 206 primary school children (106 before confinements and 100 after restrictions) completed a test battery evaluating their anthropometric characteristics, body compositions, activity preferences, cognitive performances and physical fitness. The performance of the Standing Long Jump was better at T0 (169.9 ± 142.5 cm) compared to T1 (135.2 ± 31.4 cm) (p = 0.0367), and the Medicine Ball Throw performance declined from T0 to T1 (297.3 ± 81.1 cm vs. 249 ± 52 cm; p < 0.0001). Motor skills (26.9 ± 6.2 s vs. 30.9 ± 5.4 s; p < 0.0001), the shuttle-run test (stages completed), Maximal Aerobic Speed, and the estimated VO2max were lower at T1 compared to T0 (p < 0.0001). Executive functioning was found to be greater at T0 compared to T1 (p < 0.0001). Explicit liking or wanting for sedentary or physical activities did not change between T0 and T1. Both overall physical fitness and cognitive performance drastically declined among primary school French children with the COVID-19-related public health restrictions, which reinforces the need to urgently develop preventive strategies in anticipation of further mitigation measures.

The basis of heat generated by the human body has been a source of speculation and research for more than 2,000 years. Basal heat production, now usually referred to as resting energy expenditure (REE), is currently recognized as deriving from biochemical reactions at subcellular and cellular levels that are expressed in the energy expended by the body’s 78 organs and tissues. These organs and tissues, and the 11 systems to which they belong, influence body size and shape. Connecting these subcellular‐/cellular‐level reactions to organs and tissues, and then on to body size and shape, provides a comprehensive understanding of individual differences in REE, a contemporary topic of interest in obesity research and clinical practice. This review critically examines these linkages, their association with widely used statistical and physiological REE prediction formulas, and often‐unappreciated aspects of measuring basal heat production in humans. image

Background: There is an alarming and constant worldwide progression of physical inactivity and sedentary behaviors in children and adolescents. The present paper summarizes findings from France’s 2020 Report Card on physical activity for children and youth, comparing its results to its 2 previous editions (2016 and 2018). Methods: France’s 2020 Report Card follows the standardized methodology established by the Active Healthy Kids Global Matrix, grading 10 common physical activity indicators using the best available evidence. The grades were informed by national surveys, peer-reviewed literature, government and nongovernment reports, and online information. Results: The expert panel awarded the following grades: Overall Physical Activity: D; Organized Sport Participation and Physical Activity: C−; Active Play: INC; Active Transportation: C−; Sedentary Behaviors: D−; Family and Peers: D−; Physical Fitness: D; School: B−; Community and the Built Environment: F; Government: C. Conclusions: This 2020 edition of France’s Report Card again highlights the alarming levels of physical activity and sedentary behaviors among French children and adolescents, calling for the development of effective national action. It also draws attention to the particular deleterious effects of the COVID-19 confinement on youth’s movement behaviors, which significantly worsened the situation.

Objective A previous report from our group identified directionally unfavorable dietary and lifestyle behavior trends in longitudinally monitored children and adolescents with obesity early in the COVID‐19 pandemic lockdown. The current study aimed at extending these previous observations in youths with obesity on the dietary and lifestyle behavioral consequences of the extended COVID‐19 lockdown in Verona, Italy. Methods The sample included 32 children and adolescents with obesity participating in the longitudinal OBELIX study. Diet and lifestyle information were collected pre‐pandemic, 3 weeks into the national lockdown, and 9 months later when home confinement continued to be mandatory. Changes in outcomes over the study time points were evaluated for significance using repeated‐measures ANOVA and post‐hoc pairwise t ‐tests with Bonferroni corrections. Results As previously reported, meals/day, fried potato intake, and red meat ingestion increased significantly ( p < 0.001) during the initial lockdown. Sleep time and screen time increased and sports participation decreased significantly ( p < 0.001) during the initial lockdown. These changes in health behaviors remained significantly different from baseline at the second lockdown assessment, with the exception sleep time returned to baseline levels. Conclusions Unfavorable diet and lifestyle behavioral changes in response to the initial COVID‐19 lockdown in children and adolescents with obesity have largely been sustained over the course of the pandemic. There is an urgent need to intervene on these behaviors to prevent further deleterious effects on long‐term child health; access to weight management care is critically important for these children. In addition to intervening on these behaviors, our findings should help to inform ongoing lockdown policies.

Background Visualizations of the emerging obesity epidemic, such as with serial United States (US) color prevalence maps, provide graphic images that extend informative public health messages beyond those in written communications. Advances in low-cost 3D optical technology now allows for development of large image databases that include participants varying in race/ethnicity, body mass, height, age, and circumferences. When combined with contemporary statistical methods, these data sets can be used to create humanoid avatar images with pre-specified anthropometric features. Objective The current study aimed to develop a humanoid avatar series with characteristics of representative US adults extending over the past six decades. Methods 3D optical scans were conducted on a demographically diverse sample of 570 healthy adults. Image data was converted to principal components and manifold regression equations were then developed with body mass, height, age, and waist circumference as covariates. Humanoid avatars were generated for representative adults with these four characteristics as reported in Center for Disease Control surveys beginning in 1960-62 up to 2015-18. Results There was a curvilinear increase in adult US population body mass, waist circumference, and body mass index (BMI) in males and females across the nine surveys spanning six decades. A small increase in average adult population age was present between 1960 and 2018; height changes were inconsistent. A series of four avatars developed at approximately 20-year intervals for representative males and females reveal the changes in body size and shape consistent with the emergence of the obesity epidemic. An additional series of developed avatars portray the shapes and sizes of males and females at key BMI cut points. Conclusions New mathematical approaches and accessible 3D optical technology combined with increasingly available large and diverse data sets across the lifespan now makes unique visualization of body size and shape possible on a previously unattainable scale. The study is registered at: https://clinicaltrials.gov/ct2/show/NCT03637855

Longer exclusive breastfeeding duration has been associated with differences in neural development, better satiety responsiveness, and decreased risk for childhood obesity. Given hippocampus sensitivity to diet and potential role in the integration of satiety signals, hippocampus may play a role in these relationships. We conducted a secondary analysis of 149, 7-11-year-olds (73 males) who participated in one of five studies that assessed neural responses to food cues. Hippocampal grey matter volume was extracted from structural scans using CAT12, weight status was assessed using age-and sex-adjusted body mass index (%BMI p85 ), and parents reported exclusive breastfeeding duration and satiety responsiveness (Children's Eating Behaviour Questionnaire). Separate path models for left and right hippocampus tested: (1) the direct effect of exclusive breastfeeding on satiety responsiveness and its indirect effect through hippocampal grey matter volume; (2) the direct effect of hippocampal grey matter volume on %BMI p85 and its indirect effect through satiety responsiveness. %BMI p85 was adjusted for maternal education, yearly income, and premature birth while hippocampal grey matter volume was adjusted for total intercranial volume, age, and study from which data were extracted. Longer exclusive breastfeeding duration was associated with greater bilateral hippocampal grey matter volumes. In addition, better satiety responsiveness and greater left hippocampal grey matter volume were both associated with lower %BMI p85 . However, hippocampal grey matter volumes were not associated with satiety responsiveness.Although no relationship was found between breastfeeding and child weight status, these results highlight the potential impact of exclusive breastfeeding duration on the hippocampal structure.

We conducted an online survey to examine the preference, expected burden, and willingness of people to use four different methods of assessing food and alcohol intake such as food/drink record, 24-h recall, Remote Food Photography Method© (RFPM, via SmartIntake® app), and a novel app (PortionSize®) that allows the in-app portion size estimation of foods/drinks by the user. For food (N = 1959) and alcohol (N = 466) intake assessment, 67.3% and 63.3%, respectively, preferred the RFPM/SmartIntake®, 51.9% and 53.4% preferred PortionSize®, 48.0% and 49.3% the food records, and 32.9% and 33.9% the 24-h recalls (difference in preference across all methods was p < 0.001 for food and alcohol intake). Ratings of burden and preference of methods were virtually superimposable, and we found strong correlations between high preference and low expected burden for all methods (all ρ ≥ 0.82; all p < 0.001). Willingness (mean (SD)) to use the RFPM/SmartIntake® (food: 6.6 (2.0); alcohol: 6.4 (2.4)) was greater than PortionSize® (food: 6.0 (2.2); alcohol: 6.0 (2.4); all p < 0.001) and 24-h recalls (food: 6.1 (2.2); alcohol: 5.7 (2.7); p < 0.001), but not different from food records (food: 6.6 (2.0); alcohol: 6.5 (2.3); all p ≥ 0.33). Our results can be used in conjunction with existing data on the reliability and validity of these methods in order to inform the selection of methods for the assessment of food and alcohol intake.