Gender differences in the associations between age trends of social media interaction and well-being among 10-15 year olds in the UK

Background Adolescents are among the highest consumers of social media while research has shown that their well-being decreases with age. The temporal relationship between social media interaction and well-being is not well established. The aim of this study was to examine whether the changes in social media interaction and two well-being measures are related across ages using parallel growth models. Methods Data come from five waves of the youth questionnaire, 10-15 years, of the Understanding Society, the UK Household Longitudinal Study (pooled n =9859). Social media interaction was assessed through daily frequency of chatting on social websites. Well-being was measured by happiness with six domains of life and the Strengths and Difficulties Questionnaire. Results Findings suggest gender differences in the relationship between interacting on social media and well-being. There were significant correlations between interacting on social media and well-being intercepts and between social media interaction and well-being slopes among females. Additionally higher social media interaction at age 10 was associated with declines in well-being thereafter for females, but not for males. Results were similar for both measures of well-being. Conclusions High levels of social media interaction in early adolescence have implications for well-being in later adolescence, particularly for females. The lack of an association among males suggests other factors might be associated with their reduction in well-being with age. These findings contribute to the debate on causality and may inform future policy and interventions

Interventions outside the workplace for reducing sedentary behaviour in adults under 60 years of age

Background Adults spend a majority of their time outside the workplace being sedentary. Large amounts of sedentary behaviour increase the risk of type 2 diabetes, cardiovascular disease, and both all‐cause and cardiovascular disease mortality. Objectives Primary • To assess effects on sedentary time of non‐occupational interventions for reducing sedentary behaviour in adults under 60 years of age Secondary • To describe other health effects and adverse events or unintended consequences of these interventions • To determine whether specific components of interventions are associated with changes in sedentary behaviour • To identify if there are any differential effects of interventions based on health inequalities (e.g. age, sex, income, employment) Search methods We searched CENTRAL, MEDLINE, Embase, Cochrane Database of Systematic Reviews, CINAHL, PsycINFO, SportDiscus, and ClinicalTrials.gov on 14 April 2020. We checked references of included studies, conducted forward citation searching, and contacted authors in the field to identify additional studies. Selection criteria We included randomised controlled trials (RCTs) and cluster RCTs of interventions outside the workplace for community‐dwelling adults aged 18 to 59 years. We included studies only when the intervention had a specific aim or component to change sedentary behaviour. Data collection and analysis Two review authors independently screened titles/abstracts and full‐text articles for study eligibility. Two review authors independently extracted data and assessed risk of bias. We contacted trial authors for additional information or data when required. We examined the following primary outcomes: device‐measured sedentary time, self‐report sitting time, self‐report TV viewing time, and breaks in sedentary time. Main results We included 13 trials involving 1770 participants, all undertaken in high‐income countries. Ten were RCTs and three were cluster RCTs. The mean age of study participants ranged from 20 to 41 years. A majority of participants were female. All interventions were delivered at the individual level. Intervention components included personal monitoring devices, information or education, counselling, and prompts to reduce sedentary behaviour. We judged no study to be at low risk of bias across all domains. Seven studies were at high risk of bias for blinding of outcome assessment due to use of self‐report outcomes measures. Primary outcomes Interventions outside the workplace probably show little or no difference in device‐measured sedentary time in the short term (mean difference (MD) ‐8.36 min/d, 95% confidence interval (CI) ‐27.12 to 10.40; 4 studies; I² = 0%; moderate‐certainty evidence). We are uncertain whether interventions reduce device‐measured sedentary time in the medium term (MD ‐51.37 min/d, 95% CI ‐126.34 to 23.59; 3 studies; I² = 84%; very low‐certainty evidence) We are uncertain whether interventions outside the workplace reduce self‐report sitting time in the short term (MD ‐64.12 min/d, 95% CI ‐260.91 to 132.67; I² = 86%; very low‐certainty evidence). Interventions outside the workplace may show little or no difference in self‐report TV viewing time in the medium term (MD ‐12.45 min/d, 95% CI ‐50.40 to 25.49; 2 studies; I² = 86%; low‐certainty evidence) or in the long term (MD 0.30 min/d, 95% CI ‐0.63 to 1.23; 2 studies; I² = 0%; low‐certainty evidence). It was not possible to pool the five studies that reported breaks in sedentary time given the variation in definitions used. Secondary outcomes Interventions outside the workplace probably have little or no difference on body mass index in the medium term (MD ‐0.25 kg/m², 95% CI ‐0.48 to ‐0.01; 3 studies; I² = 0%; moderate‐certainty evidence). Interventions may have little or no difference in waist circumference in the medium term (MD ‐2.04 cm, 95% CI ‐9.06 to 4.98; 2 studies; I² = 65%; low‐certainty evidence). Interventions probably have little or no difference on glucose in the short term (MD ‐0.18 mmol/L, 95% CI ‐0.30 to ‐0.06; 2 studies; I² = 0%; moderate‐certainty evidence) and medium term (MD ‐0.08 mmol/L, 95% CI ‐0.21 to 0.05; 2 studies, I² = 0%; moderate‐certainty evidence) Interventions outside the workplace may have little or no difference in device‐measured MVPA in the short term (MD 1.99 min/d, 95% CI ‐4.27 to 8.25; 4 studies; I² = 23%; low‐certainty evidence). We are uncertain whether interventions improve device‐measured MVPA in the medium term (MD 6.59 min/d, 95% CI ‐7.35 to 20.53; 3 studies; I² = 70%; very low‐certainty evidence). We are uncertain whether interventions outside the workplace improve self‐reported light‐intensity PA in the short‐term (MD 156.32 min/d, 95% CI 34.34 to 278.31; 2 studies; I² = 79%; very low‐certainty evidence). Interventions may have little or no difference on step count in the short‐term (MD 226.90 steps/day, 95% CI ‐519.78 to 973.59; 3 studies; I² = 0%; low‐certainty evidence) No data on adverse events or symptoms were reported in the included studies. Authors' conclusions Interventions outside the workplace to reduce sedentary behaviour probably lead to little or no difference in device‐measured sedentary time in the short term, and we are uncertain if they reduce device‐measured sedentary time in the medium term. We are uncertain whether interventions outside the workplace reduce self‐reported sitting time in the short term. Interventions outside the workplace may result in little or no difference in self‐report TV viewing time in the medium or long term. The certainty of evidence is moderate to very low, mainly due to concerns about risk of bias, inconsistent findings, and imprecise results. Future studies should be of longer duration; should recruit participants from varying age, socioeconomic, or ethnic groups; and should gather quality of life, cost‐effectiveness, and adverse event data. We strongly recommend that standard methods of data preparation and analysis are adopted to allow comparison of the effects of interventions to reduce sedentary behaviour

Sedentary Behaviour and Obesity: Review of the Current Scientific Evidence

1. Sedentary behaviour is not simply a lack of physical activity but is a cluster of individual behaviours where sitting or lying is the dominant mode of posture and energy expenditure is very low. 2. Sedentary behaviours are multi-faceted and might include behaviours at work or school, at home, during transport, and in leisure-time. Typically, key sedentary behaviours include screen-time (TV viewing, computer use), motorised transport, and sitting to read, talk, do homework, or listen to music. 3. Total time spent in sedentary behaviours can be captured by objective monitoring devices, such as accelerometers and inclinometers. The former can quantify the amount of time spent below a predetermined threshold of movement, and its temporal patterning across the day. Inclinometers can quantify time spent in different postures by distinguishing between lying, sitting and standing. 4. Self-reported sedentary behaviour instruments can ask respondents to report frequency and duration of time spent in different behaviours, such as TV viewing and computer game playing, over a specific time frame. 5. UK self-report data suggests that the majority of young people have ‘acceptable’ levels of TV viewing, but about one-quarter to one-third watch 4 hours per day or more, levels generally considered excessive. 6. Data on computer game playing by young people show more variability, but with up to 60% playing for more than 1 hour/day. These trends are changing rapidly and it is increasingly the case that technologies are converging. 7. According to accelerometer data, UK youth appear to spend about 420460 minutes per day in sedentary behaviour, which is about 60-65% of measured time. 8. Self-report estimates of sedentary behaviour show that approximately two-thirds of adults spend more than 2 hours per day watching TV and using the computer. 9. Significant proportions of adults report sitting for more than 5 hours per day (including work and leisure-time), and adults report spending between 3-4 hours per day sitting during their leisure-time. 10. Sedentary behaviours appear to track from childhood to adolescence or adulthood at low to moderate levels, with the strongest tracking shown for TV viewing. 11. The technological landscape is rapidly changing and evolving (for instance TV viewing on computers or internet access on TVs). This has implications for the interpretation of results from studies that may become rapidly dated. 12. Some countries have guidelines for sedentary behaviour. However, there is little or no justification given in the vast majority of recommendation documents for any time limit concerning sedentary behaviour. 13. There is a greater risk of obesity in young people with high amounts of sedentary behaviour and TV viewing at a young age being predictive of overweight as a young adult. 14. There is a positive association between sedentary time and markers of metabolic risk in young people. 15. Sedentary behaviour for adults is associated with all-cause and cardiovascular mortality, diabetes, some types of cancer and metabolic dysfunction. 16. The prospective association between sedentary behaviour and gain in body weight or the development of obesity is less clear. 17. Variables that are associated with screen-viewing in young children, and may be possible to change, include family TV viewing, snacking, body weight, parent viewing, and having a TV in the bedroom. 18. Higher BMI and depression are associated with screen-viewing in adolescents. 19. Screen-viewing tends to differ in young children by age, gender and SES; for adolescents by age, gender, ethnicity, SES, parent education; for young people by age, SES, single parent household, and ethnicity. 20. Sedentary behaviours in adults are associated with age, gender, socioeconomic conditions, occupation, weight status, and some characteristics of the physical environment. These relationships are independent of level of overall physical activity. 21. TV viewing in young people and adults is associated with a higher energy intake and poorer diet. 22. Interventions to reduce sedentary behaviour in young people, with or without the goal of changing weight status, show promise. However, given the paucity of evidence on modifiable correlates of sedentary behaviour, clear strategies to bring about successful behaviour change are still not known. 23. There is almost no evidence concerning sedentary behaviour interventions with adults. 24. Four recommendations suggest that the UK summary statements on physical activity: 1). should contain a specific recommendation that children and young people, adults, and older adults should aim to minimise the time they spend being sedentary each day; 2). should not set a quantified target for sedentary time (for people of school age and above) but should emphasize minimising time spent being sedentary each day; 3). should include specific recommendations for limiting sedentary time among children of pre-school age. These should be developed and agreed by the early years expert group; 4). should suggest the strategies to reduce sedentary behaviour

Sedentary Behaviour and Obesity: Review of the Current Scientific Evidence

1. Sedentary behaviour is not simply a lack of physical activity but is a cluster of individual behaviours where sitting or lying is the dominant mode of posture and energy expenditure is very low. 2. Sedentary behaviours are multi-faceted and might include behaviours at work or school, at home, during transport, and in leisure-time. Typically, key sedentary behaviours include screen-time (TV viewing, computer use), motorised transport, and sitting to read, talk, do homework, or listen to music. 3. Total time spent in sedentary behaviours can be captured by objective monitoring devices, such as accelerometers and inclinometers. The former can quantify the amount of time spent below a predetermined threshold of movement, and its temporal patterning across the day. Inclinometers can quantify time spent in different postures by distinguishing between lying, sitting and standing. 4. Self-reported sedentary behaviour instruments can ask respondents to report frequency and duration of time spent in different behaviours, such as TV viewing and computer game playing, over a specific time frame. 5. UK self-report data suggests that the majority of young people have ‘acceptable’ levels of TV viewing, but about one-quarter to one-third watch 4 hours per day or more, levels generally considered excessive. 6. Data on computer game playing by young people show more variability, but with up to 60% playing for more than 1 hour/day. These trends are changing rapidly and it is increasingly the case that technologies are converging. 7. According to accelerometer data, UK youth appear to spend about 420460 minutes per day in sedentary behaviour, which is about 60-65% of measured time. 8. Self-report estimates of sedentary behaviour show that approximately two-thirds of adults spend more than 2 hours per day watching TV and using the computer. 9. Significant proportions of adults report sitting for more than 5 hours per day (including work and leisure-time), and adults report spending between 3-4 hours per day sitting during their leisure-time. 10. Sedentary behaviours appear to track from childhood to adolescence or adulthood at low to moderate levels, with the strongest tracking shown for TV viewing. 11. The technological landscape is rapidly changing and evolving (for instance TV viewing on computers or internet access on TVs). This has implications for the interpretation of results from studies that may become rapidly dated. 12. Some countries have guidelines for sedentary behaviour. However, there is little or no justification given in the vast majority of recommendation documents for any time limit concerning sedentary behaviour. 13. There is a greater risk of obesity in young people with high amounts of sedentary behaviour and TV viewing at a young age being predictive of overweight as a young adult. 14. There is a positive association between sedentary time and markers of metabolic risk in young people. 15. Sedentary behaviour for adults is associated with all-cause and cardiovascular mortality, diabetes, some types of cancer and metabolic dysfunction. 16. The prospective association between sedentary behaviour and gain in body weight or the development of obesity is less clear. 17. Variables that are associated with screen-viewing in young children, and may be possible to change, include family TV viewing, snacking, body weight, parent viewing, and having a TV in the bedroom. 18. Higher BMI and depression are associated with screen-viewing in adolescents. 19. Screen-viewing tends to differ in young children by age, gender and SES; for adolescents by age, gender, ethnicity, SES, parent education; for young people by age, SES, single parent household, and ethnicity. 20. Sedentary behaviours in adults are associated with age, gender, socioeconomic conditions, occupation, weight status, and some characteristics of the physical environment. These relationships are independent of level of overall physical activity. 21. TV viewing in young people and adults is associated with a higher energy intake and poorer diet. 22. Interventions to reduce sedentary behaviour in young people, with or without the goal of changing weight status, show promise. However, given the paucity of evidence on modifiable correlates of sedentary behaviour, clear strategies to bring about successful behaviour change are still not known. 23. There is almost no evidence concerning sedentary behaviour interventions with adults. 24. Four recommendations suggest that the UK summary statements on physical activity: 1). should contain a specific recommendation that children and young people, adults, and older adults should aim to minimise the time they spend being sedentary each day; 2). should not set a quantified target for sedentary time (for people of school age and above) but should emphasize minimising time spent being sedentary each day; 3). should include specific recommendations for limiting sedentary time among children of pre-school age. These should be developed and agreed by the early years expert group; 4). should suggest the strategies to reduce sedentary behaviour