Practical quantum advantage in quantum simulation.

The development of quantum computing across several technologies and platforms has reached the point of having an advantage over classical computers for an artificial problem, a point known as 'quantum advantage'. As a next step along the development of this technology, it is now important to discuss 'practical quantum advantage', the point at which quantum devices will solve problems of practical interest that are not tractable for traditional supercomputers. Many of the most promising short-term applications of quantum computers fall under the umbrella of quantum simulation: modelling the quantum properties of microscopic particles that are directly relevant to modern materials science, high-energy physics and quantum chemistry. This would impact several important real-world applications, such as developing materials for batteries, industrial catalysis or nitrogen fixing. Much as aerodynamics can be studied either through simulations on a digital computer or in a wind tunnel, quantum simulation can be performed not only on future fault-tolerant digital quantum computers but also already today through special-purpose analogue quantum simulators. Here we overview the state of the art and future perspectives for quantum simulation, arguing that a first practical quantum advantage already exists in the case of specialized applications of analogue devices, and that fully digital devices open a full range of applications but require further development of fault-tolerant hardware. Hybrid digital-analogue devices that exist today already promise substantial flexibility in near-term applications.

Accelerometer and Survey Assessed Physical Activity in Children With Epilepsy: A Case-Controlled Study.

PURPOSE: Anecdotal evidence suggests that children with epilepsy (CWE) are limited in the frequency of their daily physical activity (PA). However, there is limited research utilizing device-based measures of PA. We compared levels of PA and sedentary behavior in CWE (11-15 y) and age- and gender-matched healthy controls. METHOD: Participants (n = 60 CWE [25 males, 35 females] and n = 49 controls [25 males, 24 females]) wore a Actigraph accelerometer (GT3X or GT3X+) for 7 consecutive days during waking hours and self-reported their PA and sedentary behaviors. CWE were compared with control children on time spent in different intensities of PA and on self-reported PA and sedentary behavior. Factors associated with PA were analyzed using linear regression. RESULTS: CWE spent less time in accelerometer assessed light (189.15 vs 215.01 min/d, P < .05) and vigorous PA (35.14 vs 44.28 min/d, P < .05) on weekdays compared with controls. There were no significant differences between CWE and control participants in accelerometer assessed time spent sedentary or time spent in PA on weekends. Among CWE, older children engaged in more reported sedentary behavior and younger children spent more time in most domains of PA (P < .05). Furthermore, CWE reported less PA than controls (P = .006). Sixteen percent of controls met World Health Organization PA guidelines compared with 10% of CWE. There was a positive relationship between accelerometer assessed PA and quality of life for CWE. CONCLUSION: CWE spent less time in light and moderate to vigorous PA on weekdays. Further research is needed to understand reasons for these differences.

Clustering of diet, physical activity and sedentary behaviour and related physical and mental health outcomes: a systematic review.

BACKGROUND: Physical activity (PA), sedentary behaviour (SB) and diet play an important role in the physical and mental health of young people. Understanding how these behaviours cluster, and the impact of clusters on health is important for the development of public health interventions. This review examines the prevalence of clusters of PA, sedentary time, and dietary behaviours, and how clusters relate to physical and mental health indicators among children, adolescents and young adults. METHODS: Electronic (PubMed, Web of Science and Scopus) and manual searches were conducted for articles that were (i) observational studies including children, adolescents and/or young adults aged 5-24 years, (ii) examined the 'patterning', 'clustering', or 'co-existence' of each of PA, dietary behaviour and SB, and (iii) published in English up to and including July 2022. In addition to information on clustering, data on physical and mental health outcomes were extracted where reported. Included studies were assessed using the Cochrane risk of bias for observational studies. A narrative synthesis was conducted due to high heterogeneity. This review was registered with PROSPERO (CRD42021230976). RESULTS: Forty-nine cross-sectional studies and four prospective cohort studies from eighteen countries reporting data from 778,415 individual participants were included. A broad range of clusters (n = 172) were found (healthy, unhealthy, and mixed). Mixed clusters were common (n = 98), and clusters of high diet quality, low PA and high SB were more prevalent in girls, while mixed clusters of high PA, high SB and low diet quality were more prevalent in boys. Unhealthy clusters comprising low moderate to vigorous PA, low consumption of fruits and vegetables, and high screen time were prevalent, particularly in those from lower socioeconomic status families. Compared to those with healthy behavioural clusters, those with unhealthy and mixed clusters had a higher adiposity, higher risk of cardiovascular disease, poorer mental health scores, and lower cardiorespiratory fitness. CONCLUSIONS: PA, SB and diet cluster in healthy, unhealthy and mixed patterns in young people that differ across sociodemographic characteristics. Unhealthy clusters are associated with poorer health outcomes. Intervention strategies targeting un-clustering multiple unhealthy behaviours should be developed and evaluated for their impact on health outcomes.

The Association of Contemporary Screen Behaviours with Physical Activity, Sedentary Behaviour and Sleep in Adolescents: a Cross-sectional Analysis of the Millennium Cohort Study.

BACKGROUND: Screen behaviours are highly prevalent in adolescents and may be adversely associated with physical and mental health. Understanding how screen behaviours inter-relate with physical activity and sleep may help to clarify pathways through which they impact health and potential routes to behaviour change. This cross-sectional study examines the association of contemporary screen behaviours with physical activity, sedentary behaviour and sleep in adolescents. METHOD: Data are from sweep 6 (2015/2016) of the Millennium Cohort Study, conducted when participants were aged 14 years. Outcome variables were accelerometer-assessed overall physical activity and moderate-to-vigorous physical activity (MVPA), self-reported sedentary behaviour and sleep duration. Screen behaviours were assessed using a 24-h time-use diary. Multivariable regression was used to examine the association between screen behaviours and each outcome variable separately for weekdays and weekend days. RESULTS: The use of social network sites was associated with (beta coefficient, 95% confidence interval (CI); minutes/day) less time in MVPA (weekdays: - 5.2 (- 10.3, - 0.04); weekend: - 10.0 (- 15.5, - 4.5)), and sedentary behaviours (weekdays: - 19.8 (- 31.0, - 8.6); weekend: - 17.5 (- 30.9, - 4.1)). All screen behaviours were associated with shorter sleep duration on weekdays, whereas only the use of email/texts and social network sites was associated with shorter sleep duration on weekend days. The association of using social network sites with overall physical activity was stronger in girls than in boys; the association of internet browsing with sedentary behaviour was stronger in boys than in girls. CONCLUSION: Intervention strategies to enhance MVPA and sleep duration by limiting screen-based activities may be warranted.

Is the positive relationship of infant weight gain with adolescent adiposity attenuated by moderate-to-vigorous physical activity in childhood? Evidence from the Millennium Cohort Study.

OBJECTIVE: Rapid infant weight gain is a key risk factor for paediatric obesity, yet there is very little evidence on how healthy behaviours in childhood might modify this association. We aimed to examine how the association of infant weight gain with adolescent adiposity might be attenuated by moderate-to-vigorous physical activity (MVPA) in childhood. METHODS: The sample comprised 4666 children in the UK Millennium Cohort Study. The two outcomes were BMI Z-score and % fat at 14 years. Sex-stratified regression models were developed testing for interactions between infant weight Z-score gain between 0 and 3 years (continuous or categorical) and MVPA at 7 years (continuous or binary). Models were sequentially adjusted for basic covariates, socioeconomic variables, and parental BMI levels. RESULTS: Effect modification was observed in boys but not girls and, among boys, was stronger for % fat than BMI. In a fully adjusted model for boys, the association between infant weight Z-score gain and adolescent % fat was 1.883 (1.444, 2.322) if MVPA < 60 min/day and 1.305 (0.920, 1.689) if MVPA ≥ 60 min/day; the difference between these two estimates being -0.578 (-1.070, -0.087). Similarly, % fat was 2.981 (1.596, 4.367) units higher among boys who demonstrated rapid infant weight gain (+0.67 to +1.34 Z-score) compared to normal weight gain (-0.67 to +0.67 Z-scores), but having MVPA ≥ 60 min/day reduced this effect size by -2.259 (-3.989, -0.535) units. CONCLUSIONS: In boys, ~75% of the excess % fat at 14 years associated with rapid infant weight gain was attenuated by meeting the MVPA guideline. In boys known to have demonstrated rapid infant weight gain, increasing childhood MVPA levels, with the target of ≥60 min/day, might therefore go a long way to towards offsetting their increased risk for adolescent obesity. The lack of effect modification in girls is likely due to lower MVPA levels.

Feasibility of Measuring Sedentary Time Using Data From a Thigh-Worn Accelerometer.

In large-scale cohort studies, sedentary behavior has been routinely measured using self-reports or devices that apply a count-based threshold. We employed a gold standard postural allocation technique using thigh inclination and acceleration to capture free-living sedentary behavior. Participants aged 46.8 (standard deviation (SD), 0.7) years (n = 5,346) from the 1970 British Cohort Study (United Kingdom) were fitted with a waterproofed thigh-mounted accelerometer device (activPAL3 micro; PAL Technologies Ltd., Glasgow, United Kingdom) worn continuously over 7 days; data were collected in 2016-2018. Usable data were retrieved from 83.0% of the devices fitted, with 79.6% of the sample recording at least 6 full days of wear (at least 10 waking hours). Total daily sitting time (average times were 9.5 (SD, 2.0) hours/day for men and 9.0 (SD, 2.0) hours/day for women) accounted for 59.4% and 57.3% of waking hours in men and women, respectively; 73.8% of sample participants recorded ≥8 hours/day of sitting. Sitting in prolonged bouts of 60 continuous minutes or more accounted for 25.3% and 24.4% of total daily sitting in men and women, respectively. In mutually adjusted models, male sex, underweight, obesity, education, poor self-rated health, television-viewing time, and having a sedentary occupation were associated with higher device-measured sitting times. Thigh-worn accelerometry was feasibly deployed and should be considered for larger-scale national surveys.

Stand Out in Class: restructuring the classroom environment to reduce sitting time - findings from a pilot cluster randomised controlled trial.

BACKGROUND: Excessive sedentary behaviour (sitting) is a risk factor for poor health in children and adults. Incorporating sit-stand desks in the classroom environment has been highlighted as a potential strategy to reduce children's sitting time. The primary aim of this study was to examine the feasibility of conducting a cluster randomised controlled trial (RCT) of a sit-stand desk intervention within primary school classrooms. METHODS: We conducted a two-armed pilot cluster RCT involving 8 primary schools in Bradford, United Kingdom. Schools were randomised on a 1:1 basis to the intervention or usual practice control arm. All children (aged 9-10 years) in participating classes were eligible to take part. Six sit-stand desks replaced three standard desks (sitting 6 children) in the intervention classrooms for 4.5-months. Teachers were encouraged to use a rotation system to ensure all pupils were exposed to the sit-stand desks for > 1 h/day on average. Trial feasibility outcomes (assessed using quantitative and qualitative measures) included school and participant recruitment and attrition, intervention and outcome measure completion rates, acceptability, and preliminary effectiveness of the intervention for reducing sitting time. A weighted linear regression model compared changes in weekday sitting time (assessed using the activPAL accelerometer) between trial arms. RESULTS: School and child recruitment rates were 33% (n = 8) and 75% (n = 176). At follow-up, retention rates were 100% for schools and 97% for children. Outcome measure completion rates ranged from 63 to 97%. A preliminary estimate of intervention effectiveness revealed a mean difference in change in sitting of - 30.6 min/day (95% CI: - 56.42 to - 4.84) in favour of the intervention group, after adjusting for baseline sitting and wear time. Qualitative measures revealed the intervention and evaluation procedures were acceptable to teachers and children, except for some problems with activPAL attachment. CONCLUSION: This study provides evidence of the acceptability and feasibility of a sit-stand desk intervention and evaluation methods. Preliminary evidence suggests the intervention showed potential in reducing children's weekday sitting but some adaptations to the desk rotation system are needed to maximize exposure. Lessons learnt from this trial will inform the planning of a definitive trial. TRIAL REGISTRATION: ISRCTN12915848 (registered: 09/11/16).

Reducing screen-time and unhealthy snacking in 9-11 year old children: the Kids FIRST pilot randomised controlled trial.

BACKGROUND: Many young people form unhealthy behavioural habits, such as low intake of fruit and vegetables, high intake of energy-dense snack foods, and excessive sedentary screen-based behaviours. However, there is a shortage of parent-and home-focused interventions to change multiple health behaviours in children. METHODS: Kids FIRST was a 12-week, home- and school-based pilot randomised controlled trial to reduce screen-time and unhealthy snacking with assessments at pre- (baseline) and post-intervention. Four UK schools were randomised to control or one of three interventions targeting reductions in (1) screen-time and unhealthy snacking (ST + Sn), (2) screen-time (ST only), (3) unhealthy snacking (Sn only), and parents with children aged 9-11 years were recruited via schools. Intervention group parents received four online 'sessions' and four packages of resources tailored to each group. Children received four 30-min lessons during school time. Children and parents reported their own screen-time behaviours, children reported their own snacking behaviours. Descriptive analyses were undertaken using principles of intention to treat. RESULTS: Initial feasibility was shown in that this study successfully recruited schools and families into all four study arms and retained them over a period of 13 weeks (retention rate ≥ 74%). Seventy-five children and 64 parents provided full baseline questionnaire data. Reductions in children's school day and weekend day TV/DVD viewing and computer game use were found in the ST + Sn and ST groups, while self-reported smartphone use increased in these groups. Similar results were found for parents' TV/DVD, computer and smartphone use in these groups. Little to no changes were found in reports of the dietary variables assessed in any intervention group for children or parents. CONCLUSIONS: These preliminary findings show some promise for the Kids FIRST intervention. Based on these findings, a future full trial should recruit a more diverse sample of families and optimise the intervention and intervention resources to more fully engage parents with the dietary-based components of the intervention programme, where fewer changes were seen. Although most parents reporting receiving the intervention resources, further development work is required to achieve higher levels of engagement. This might include greater parent and child engagement work early in the development of the project. TRIAL REGISTRATION: Retrospectively registered in June 21st 2019 with ClinicalTrials.gov (number NCT03993652).

activPAL-measured sitting levels and patterns in 9-10 years old children from a UK city.

BACKGROUND: There is insufficient evidence of sitting time in UK children from validated objective measures. This study explored sitting patterns in primary school children from Bradford, UK, using the validated activPAL inclinometer. METHODS: Overall, 79 children (9.8 (SD 0.3) years old, 52% boys; 70% South Asian) wore activPALs for 7 days. Total sitting time, sitting time accumulated in different bout lengths, and the proportion of wear time spent in these variables were explored and compared across different periods of the week. RESULTS: Children spent 614 ± 112 (median ± IQR) min/day on school days and 690 ± 150 min/day on weekend days sitting. The proportion of time spent sitting was significantly higher on weekend days compared to school days (mean±SD: 74 ± 10% versus 68 ± 8%,P < 0.001), as was the proportion of time accumulated in >30 min sitting bouts (mean±CI: 28 ± 27-33% versus 20 ± 20-22%, P < 0.001). The proportion of time spent sitting after school was significantly higher than during school time (mean±SD: 70 ± 8.4% versus 63 ± 8.3%,P < 0.001), as was the proportion of time spent in prolonged (>30 min) sitting bouts (mean±CI: 19 ± 16-22% versus 11 ± 10-14%, P < 0.001). CONCLUSIONS: Children spent large proportions of their waking day sitting, often accumulated in prolonged uninterrupted bouts and particularly after school and on weekends. Interventions to reduce sitting time in children are urgently needed.

Sedentary Behaviors and Adiposity in Young People: Causality and Conceptual Model.

Research on sedentary behavior and adiposity in youth dates back to the 1980s. Sedentary behaviors, usually screen time, can be associated with adiposity. Although the association usually is small but significant, the field is complex, and results are dependent on what sedentary behaviors are assessed and may be mediated and moderated by other behaviors.

Clustering and correlates of screen-time and eating behaviours among young children.

BACKGROUND: Screen-time and unhealthy dietary behaviours are highly pervasive in young children and evidence suggests that these behaviours often co-occur and are associated. Identifying clusters of unhealthy behaviours, and their influences early in childhood, can assist in the development of targeted preventive interventions. The purpose of this study was to examine the sociodemographic, behavioural, and home physical environmental correlates of co-occurring screen-time and unhealthy eating behaviours and to assess the clustering of screen-time and unhealthy dietary behaviours in young children. METHODS: Parents of 126 children, from the UK, aged 5-6 years (49% boys) completed a questionnaire which assessed their child's screen-time (ST), fruit and vegetable (FV), and energy-dense (ED) snack consumption. Categories of health behaviours were created based on frequencies of children meeting recommendations for FV and ST and median splits of frequencies for ED snacks. Parents reported on their own behaviours (ST, FV, and ED snack consumption), how often they ate meals and watched TV with their child, and on the availability and accessibility of foods within the home. An observed over expected ratio (O/E) was used to assess behavioural clustering. Multivariable multinomial logistic regression was used to examine correlates of behaviour patterns. RESULTS: Approximately 25% of children had two or three health risk behaviours. Correlates consistently associated with clusters included parental income, eating meals at the TV, parental ST and ED snack food consumption, and home availability of ED snack foods. Observed over expected ratios were close to 1 and ranged from 0.78 to 1.43. The three-risk behaviour combination of insufficient FV consumption, high ED snack consumption, and excessive ST occurred more frequently than expected (1.23 (95% CI 0.89, 1.58)). CONCLUSIONS: ST and unhealthy dietary behaviours cluster in children as young as 5 years of age and parents' own behaviours appear to be important influencing factors. Further research into the development of behavioural clustering in young children to identify and further understand the mechanisms underlying the synergy among health behaviours is needed. Feasibility interventions promoting reductions in both screen-time and unhealthy dietary behaviours reciprocally, while simultaneously focusing on changing parental behaviours, are warranted.

Sedentary behaviour across the primary-secondary school transition: A systematic review.

The transition from primary/middle school to secondary/high school is likely to be a key period in children's development, characterised by significant changes in their social and physical environment. However, little is known about the changes in sedentary behaviour that accompany this transition. This review aimed to identify, critically appraise and summarise the evidence on changes in sedentary behaviour across the primary - secondary school transition. Published English language studies were located from computerised and manual searches in 2015. Inclusion criteria specified a longitudinal design, baseline assessment when children were in primary/middle school with at least one follow-up during secondary/high school and a measure of sedentary behaviour at both (or all) points of assessment. Based on data from 11 articles (19 independent samples), tracking coefficients were typically in the range of 0.3 to 0.5 and relatively consistent across the different sedentary behaviours examined and durations of follow-up. Both screen-based sedentary behaviour and overall sedentary time increased during the school transition. Overall there was an increase of approximately 10-20min per day per year in accelerometer-assessed sedentary time. Consistent with the broader age-related changes in behaviour observed during this period, sedentary behaviour increases during the transition from primary/middle to secondary/high school. Investigating features of the social and physical environment that might exacerbate or attenuate this trend would be a valuable next step.

Clustering and correlates of screen-time and eating behaviours among young adolescents.

BACKGROUND: Screen-time and eating behaviours are associated in adolescents, but few studies have examined the clustering of these health behaviours in this age group. The identification of clustered health behaviours, and influences on adolescents' clustered health behaviours, at the time when they are most likely to become habitual, is important for intervention design. The purpose of this study was to assess the prevalence and clustering of health behaviours in adolescents, and examine the sociodemographic, individual, behavioural, and home social and physical environmental correlates of clustered health behaviours. METHODS: Adolescents aged 11-12 years (n = 527, 48% boys) completed a questionnaire during class-time which assessed screen-time (ST), fruit and vegetable (FV), and energy-dense (ED) snack consumption using a Food Frequency Questionnaire. Health behaviours were categorised into high and low frequencies based on recommendations for FV and ST and median splits for ED snacks. Adolescents reported on their habits, self-efficacy, eating at the television (TV), eating and watching TV together with parents, restrictive parenting practices, and the availability and accessibility of foods within the home. Behavioural clustering was assessed using an observed over expected ratio (O/E). Correlates of clustered behaviours were examined using multivariate multinomial logistic regression. RESULTS: Approximately 70% reported having two or three health risk behaviours. Overall, O/E ratios were close to 1, which indicates clustering. The three risk behaviour combination of low FV, high ED, and high ST occurred more frequently than expected (O/E ratio = 1.06 95% CI 1.01, 1.15. Individual, behavioural, and social and physical home environmental correlates were differentially associated with behavioural clusters. Correlates consistently associated with clusters included eating ED snacks while watching TV, eating at the TV with parents, and the availability and accessibility of ED snack foods within the home. CONCLUSIONS: There is a high prevalence of screen time and unhealthy eating, and screen time is coupled with unhealthy dietary behaviours. Strategies and policies are required that simultaneously address reductions in screen time and changes to habitual dietary patterns, such as TV snacking and snack availability and accessibility. These may require a combination of individual, social and environmental changes alongside conscious and more automatic (nudging) strategies.

Individual, behavioural and home environmental factors associated with eating behaviours in young adolescents.

This study aimed to examine individual, behavioural and home environmental factors associated with frequency of consumption of fruit, vegetables and energy-dense snacks among adolescents. Adolescents aged 11-12 years (n = 521, 48% boys) completed a paper-based questionnaire during class-time which included a Food Frequency Questionnaire assessing their consumption of fruit, vegetables, and energy-dense (ED) snacks, and items assessing habits, self-efficacy, eating at the television (TV), eating with parents, parenting practices, and home availability and accessibility of foods. Multiple linear regression analyses showed that eating fruit and vegetables while watching TV and home availability and accessibility of fruit and vegetables were positively associated with frequency of fruit consumption and vegetable consumption, while home accessibility of ED snack foods was negatively associated with frequency of fruit consumption. Habit for eating ED snack foods in front the TV, eating ED snack foods while watching TV, and home availability of ED snacks were positively associated with frequency of ED snack consumption. This study has highlighted the importance of a healthy home environment for promoting fruit and vegetable intake in early adolescents and also suggests that, if snacking while TV viewing occurs, this could be a good opportunity for promoting fruit and vegetable intake. These findings are likely to be useful for supporting the development of multi-faceted interventions and aid us in knowing what advice to give to parents to help them to help their young adolescents to develop and maintain healthy eating habits.

Reducing children's classroom sitting time using sit-to-stand desks: findings from pilot studies in UK and Australian primary schools.

BACKGROUND: This research examined the influence of sit-to-stand desks on classroom sitting time in primary school children. METHODS: Pilot controlled trials with similar intervention strategies were conducted in primary schools in Melbourne, Australia, and Bradford, UK. Sit-to-stand desks replaced all standard desks in the Australian intervention classroom. Six sit-to-stand desks replaced a bank of standard desks in the UK intervention classroom. Children were exposed to the sit-to-stand desks for 9-10 weeks. Control classrooms retained their normal seated desks. Classroom sitting time was measured at baseline and follow-up using the activPAL3 inclinometer. RESULTS: Thirty UK and 44 Australian children provided valid activPAL data at baseline and follow-up. The proportion of time spent sitting in class decreased significantly at follow-up in both intervention groups (UK: -9.8 ± 16.5% [-52.4 ± 66.6 min/day]; Australian: -9.4 ± 10% [-43.7 ± 29.9 min/day]). No significant changes in classroom sitting time were observed in the UK control group, while a significant reduction was observed in the Australian control group (-5.9 ± 11.7% [-28.2 ± 28.3 min/day]). CONCLUSIONS: Irrespective of implementation, incorporating sit-to-stand desks into classrooms appears to be an effective way of reducing classroom sitting in this diverse sample of children. Longer term efficacy trials are needed to determine effects on children's health and learning.

Devices for Self-Monitoring Sedentary Time or Physical Activity: A Scoping Review.

BACKGROUND: It is well documented that meeting the guideline levels (150 minutes per week) of moderate-to-vigorous physical activity (PA) is protective against chronic disease. Conversely, emerging evidence indicates the deleterious effects of prolonged sitting. Therefore, there is a need to change both behaviors. Self-monitoring of behavior is one of the most robust behavior-change techniques available. The growing number of technologies in the consumer electronics sector provides a unique opportunity for individuals to self-monitor their behavior. OBJECTIVE: The aim of this study is to review the characteristics and measurement properties of currently available self-monitoring devices for sedentary time and/or PA. METHODS: To identify technologies, four scientific databases were systematically searched using key terms related to behavior, measurement, and population. Articles published through October 2015 were identified. To identify technologies from the consumer electronic sector, systematic searches of three Internet search engines were also performed through to October 1, 2015. RESULTS: The initial database searches identified 46 devices and the Internet search engines identified 100 devices yielding a total of 146 technologies. Of these, 64 were further removed because they were currently unavailable for purchase or there was no evidence that they were designed for, had been used in, or could readily be modified for self-monitoring purposes. The remaining 82 technologies were included in this review (73 devices self-monitored PA, 9 devices self-monitored sedentary time). Of the 82 devices included, this review identified no published articles in which these devices were used for the purpose of self-monitoring PA and/or sedentary behavior; however, a number of technologies were found via Internet searches that matched the criteria for self-monitoring and provided immediate feedback on PA (ActiGraph Link, Microsoft Band, and Garmin Vivofit) and sedentary time (activPAL VT, the Lumo Back, and Darma). CONCLUSIONS: There are a large number of devices that self-monitor PA; however, there is a greater need for the development of tools to self-monitor sedentary time. The novelty of these devices means they have yet to be used in behavior change interventions, although the growing field of wearable technology may facilitate this to change.

Energy expenditure during common sitting and standing tasks: examining the 1.5 MET definition of sedentary behaviour.

BACKGROUND: Sedentary behavior is defined as any waking behavior characterized by an energy expenditure of 1.5 METS or less while in a sitting or reclining posture. This study examines this definition by assessing the energy cost (METs) of common sitting, standing and walking tasks. METHODS: Fifty one adults spent 10 min during each activity in a variety of sitting tasks (watching TV, Playing on the Wii, Playing on the PlayStation Portable (PSP) and typing) and non-sedentary tasks (standing still, walking at 0.2, 0.4, 0.6, 0.8, 1.0, 1.2, 1.4, and 1.6 mph). Activities were completed on the same day in a random order following an assessment of resting metabolic rate (RMR). A portable gas analyzer was used to measure oxygen uptake, and data were converted to units of energy expenditure (METs). RESULTS: Average of standardized MET values for screen-based sitting tasks were: 1.33 (SD: 0.24) METS (TV), 1.41 (SD: 0.28) (PSP), and 1.45 (SD: 0.32) (Typing). The more active, yet still seated, games on the Wii yielded an average of 2.06 (SD: 0.5) METS. Standing still yielded an average of 1.59 (SD: 0.37) METs. Walking MET values increased incrementally with speed from 2.17 to 2.99 (SD: 0.5 - 0.69) METs. CONCLUSIONS: The suggested 1.5 MET threshold for sedentary behaviors seems reasonable however some sitting based activities may be classified as non-sedentary. The effect of this on the definition of sedentary behavior and associations with metabolic health needs further investigation.

Sedentary behaviour and diet across the lifespan: an updated systematic review.

BACKGROUND: Sedentary behaviour and its association with dietary intake in young people and adults are important topics and were systematically reviewed in 2011. There is a need to update this evidence given the changing nature of sedentary behaviour and continued interest in this field. This review aims to assist researchers in better interpreting the diversity of findings concerning sedentary behaviour and weight status. OBJECTIVE: To provide an update of the associations between sedentary behaviour and dietary intake across the lifespan. METHODS: Electronic databases searched were MEDLINE, PsychInfo, Cochrane Library, Web of Science and Science Direct for publications between January 2010 and October 2013, thus updating a previous review. Included were observational studies assessing an association between at least one sedentary behaviour and at least one aspect of dietary intake in preschool children (<5 years), school-aged children (6-11 years), adolescents (12-18 years) and adults (>18 years). RESULTS: 27 papers met inclusion criteria (preschool k=3, school-aged children k=9, adolescents k=15, adults k=3). For all three groups of young people, trends were evident for higher levels of sedentary behaviour, especially TV viewing, to be associated with a less healthful diet, such as less fruit and vegetable and greater consumption of energy-dense snacks and sugar sweetened beverages. Data for the three studies with adults were less conclusive. CONCLUSIONS: Sedentary behaviour continues to be associated with unhealthy diet in young people in mostly cross-sectional studies. More studies utilising a prospective design are needed to corroborate findings and more studies are needed with adults.

The effectiveness of interventions to increase physical activity among young girls: a meta-analysis.

CONTEXT: Pre-adolescent girls are an important target population for physical activity behaviour change as it may enhance tracking into the crucial period of adolescence. The quantification of intervention effectiveness for this age group of girls has not been previously reported. EVIDENCE ACQUISITION: Studies published in English up to and including August 2013 were located from computerised (MedLine, PsychInfo, Science Direct, Web of Science, EPPI centre databases, and Cochrane Library database) and manual searches. Intervention studies aimed at promoting physical activity, which included pre-adolescent girls aged 5-11 years, and a non-physical activity control/comparison group were included. EVIDENCE SYNTHESIS: A random effects meta-analysis was conducted. The average treatment effect for pre-adolescent girls involved in physical activity interventions was significant but small (g=0.314, p<.001). Moderator analyses showed larger effects for interventions that catered for girls only and used educational and multicomponent strategies. CONCLUSIONS: Interventions to increase physical activity in pre-adolescent girls show small but significant effects, suggesting that behaviour change may be challenging, but results suggest some strategies that could be successful.

The relationship between sedentary behaviour and physical activity in adults: a systematic review.

To ascertain, through a systematic review, the associations between sedentary behaviour (SB) and physical activity (PA) among adults aged 18-60years. Studies published in English up to and including June 2013 were located from computerized and manual searches. Studies reporting on at least one measure of SB and an association with one measure of PA were included. 26 studies met the inclusion criteria. Six studies examined associations between SB and PA prospectively, and 20 were cross-sectional. The most commonly assessed subtype of sedentary behaviours were television viewing (11 studies), total sedentary time (10), total sitting time (4), general screen time (3) and occupational sedentary time (2). All studied types of SB were associated with lower levels of PA in adults. Findings of this review suggest inverse associations between SB and PA were weak to moderate. Objective monitoring studies reported larger negative associations between SB and light intensity activity. Current evidence, though limited, supports the notion that sedentary behaviour displaces light intensity activity.