Improving the design and implementation of evidence-based practice depends on successful behaviour change interventions. This requires an appropriate method for characterising interventions and linking them to an analysis of the targeted behaviour. There exists a plethora of frameworks of behaviour change interventions, but it is not clear how well they serve this purpose. This paper evaluates these frameworks, and develops and evaluates a new framework aimed at overcoming their limitations. A systematic search of electronic databases and consultation with behaviour change experts were used to identify frameworks of behaviour change interventions. These were evaluated according to three criteria: comprehensiveness, coherence, and a clear link to an overarching model of behaviour. A new framework was developed to meet these criteria. The reliability with which it could be applied was examined in two domains of behaviour change: tobacco control and obesity. Nineteen frameworks were identified covering nine intervention functions and seven policy categories that could enable those interventions. None of the frameworks reviewed covered the full range of intervention functions or policies, and only a minority met the criteria of coherence or linkage to a model of behaviour. At the centre of a proposed new framework is a 'behaviour system' involving three essential conditions: capability, opportunity, and motivation (what we term the 'COM-B system'). This forms the hub of a 'behaviour change wheel' (BCW) around which are positioned the nine intervention functions aimed at addressing deficits in one or more of these conditions; around this are placed seven categories of policy that could enable those interventions to occur. The BCW was used reliably to characterise interventions within the English Department of Health's 2010 tobacco control strategy and the National Institute of Health and Clinical Excellence's guidance on reducing obesity. Interventions and policies to change behaviour can be usefully characterised by means of a BCW comprising: a 'behaviour system' at the hub, encircled by intervention functions and then by policy categories. Research is needed to establish how far the BCW can lead to more efficient design of effective interventions.

Understanding the determinants of changing physical activity among older adults is crucial for effective intervention development. The aim of this study was to review and update the evidence relating to the determinants of physical activity initiation and maintenance among older adults, and to explore the main similarities and dissimilarities in determinants between the two phases. Only longitudinal and experimental studies were used to assess the level of evidence. Fifty-nine longitudinal observational and experimental studies were identified. Recent studies were identified that focused on some recently developed concepts, especially in the field of the post-motivational concepts and several environmental determinants in predicting physical activity initiation and maintenance. Furthermore, dissimilarities were found in determinants between physical activity initiation and maintenance. It can be concluded that determinants are to a large degree phase-specific, which should be taken into account during further investigation, theory development and intervention development. Further investigation is needed to study the importance of promising concepts, such as post-motivational and environmental determinants. Recommendations for further empirical research, theory development and intervention development are outlined in this review.

Summary: Background: Discerning the determinants of weight loss maintenance is important in the planning of future interventions and policies regarding overweight and obesity. We have therefore systematically synthesized recent literature on determinants of weight loss maintenance for individuals with overweight and obesity.Methods: With the use of the Preferred Reporting Items for Systematic Reviews and Meta‐Analyses statement, prospective studies were identified from searches in PubMed and PsycINFO from 2006 to 2016. We included articles investigating adults with overweight and obesity undergoing weight loss without surgery or medication. Included articles were scored on their methodological quality, and a best‐evidence synthesis was applied to summarize the results.Results: Our search resulted in 8,222 articles of which 67 articles were selected. In total, 124 determinants were identified of which 5 were demographic, 59 were behavioural, 51 were psychological/cognitive and 9 were social and physical environmental determinants. We found consistent evidence that demographic determinants were not predictive of weight loss maintenance. Behavioural and cognitive determinants that promote a reduction in energy intake, an increase in energy expenditure and monitoring of this balance are predictive determinants.Conclusion: This review identifies key determinants in weight loss maintenance. However, more research regarding cognitive and environmental determinants of weight loss maintenance is needed to advance our knowledge on determinants of weight loss maintenance.

Current data on the prevalence of overweight and energy-balance behaviors among European children is necessary to inform overweight prevention interventions. A school-based survey among 10–12 year old children was conducted in seven European countries using a standardized protocol. Weight, height, and waist circumference were measured; Engagement in physical activity, sedentary and dietary behaviors, and sleep duration were self-reported. Descriptive analyses were conducted, looking at differences according to country, gender, and parental education. 7234 children (52%girls; 11.6±0.7 years) participated. 25.8% and 5.4% of boys, and 21.8% and 4.1% of girls were overweight (including obese) and obese (according to International Obesity Task Force criteria), respectively. Higher prevalence of overweight/obesity was observed in Greece, Hungary, Slovenia and Spain than in Belgium, Netherlands and Norway. Large differences between countries were found in intakes of sugar-sweetened beverages, breakfast, active transport, TV and computer time. More favorable overweight status and behavior patterns were found in girls than boys and in children of higher educated parents than in children of lower educated parents. High levels and striking differences in overweight status and potential risk behaviors were found among schoolchildren across Europe.

Lack of physical activity (PA) and high levels of sedentary behaviour (SB) have been associated with health problems. This systematic review evaluates the effectiveness of school-based interventions to increase PA and decrease SB among 15–19-year-old adolescents, and examines whether intervention characteristics (intervention length, delivery mode and intervention provider) and intervention content (i.e. behaviour change techniques, BCTs) are related to intervention effectiveness. A systematic search of randomised or cluster randomised controlled trials with outcome measures of PA and/or SB rendered 10 results. Risk of bias was assessed using the Cochrane risk of bias tool. Intervention content was coded using Behaviour Change Technique Taxonomy v1. Seven out of 10 studies reported significant increases in PA. Effects were generally small and short-term (Cohen's d ranged from 0.132 to 0.659). Two out of four studies that measured SB reported significant reductions in SB. Interventions that increased PA included a higher number of BCTs, specific BCTs (e.g., goal setting, action planning and self-monitoring), and were delivered by research staff. Intervention length and mode of delivery were unrelated to effectiveness. More studies are needed that evaluate long-term intervention effectiveness and target SBs among older adolescents.

Introduction: The prevalence and clinical significance of weight regain after bariatric surgery remains largely unclear due to the lack of a standardized definition of significant weight regain. The development of a clinically relevant definition of weight regain requires a better understanding of its clinical significance. Objectives: To assess rates of weight regain 5 years after Roux-en-Y gastric bypass (RYGB) and sleeve gastrectomy (SG), applying six definitions and investigating their association with clinical outcomes. Methods: Patients were followed up until 5 years after surgery and weight regain was calculated. Regression techniques were used to assess the association of weight regain with health-related quality of life (HRQoL) and the presence of comorbidities. Results: A total of 868 patients participated in the study, with a mean age of 46.6 (± 10.4) years, of which 79% were female. The average preoperative BMI was 44.8 (± 5.9) kg/m² and the total maximum weight loss was 32% (± 8%). Eighty-seven percent experienced any regain. Significant weight regain rates ranged from 16 to 37% depending on the definition. Three weight regain definitions were associated with deterioration in physical HRQoL (p < 0.05), while associations between definitions of weight regain and the presence of comorbidities 5 years after surgery were not significant. Conclusion: These results indicate that identifying one single categorical definition of clinically significant weight regain is difficult. Additional research into the clinical significance of weight regain is needed to inform the development of a standardized definition that includes all dimensions of surgery success: weight, HRQoL, and comorbidity remission.