An exploration of childhood obesity treatment interventions to enhance their long-term effectiveness.

Childhood obesity is a major public health concern. Recent data suggests although childhood obesity prevalence rates appear to be slowing, they are still unacceptably high (Health Survey for England, 2010). To establish a downward trend in childhood obesity rates, effective treatment options are vital. To date, multi-component treatment interventions (MCTIs) incorporating a physical activity, healthy eating and behavioural component and encouraging family involvement appear to be the most promising approach to treat childhood obesity. However, no firm conclusion can be made regarding the sustainability of treatment outcomes (i.e. behavioural & weight related outcomes) (Luutikhuis et al., 2009). This thesis contributed to the evidence base regarding the sustainability of treatment outcomes from MCTIs; considered stakeholder views in the intervention design process and provided an insight into treatment recipient's reasons for attrition from MCTIs.To critically examine the evidence base, Study 1 provided a systematic review of childhood obesity treatment interventions. Results revealed gaps in the evidence in terms of how best to maintain treatment outcomes. Furthermore the study highlighted a need to better consider stakeholder views in intervention design and to fully report treatment fidelity (TF). In Study 2, a qualitative inquiry explored stakeholder perspectives towards childhood obesity treatment and the maintenance of treatment outcomes. Results revealed incongruence between treatment recipients (i.e. parents & children) and treatment deliverers (i.e. health professionals). Treatment recipients suggested they required ongoing support to maintain treatment outcomes. Conversely, treatment deliverers suggested ongoing support is unrealistic and MCTIs should create autonomous individuals who feel confident in their ability to maintain treatment outcomes. Implications included the need to consider maintenance strategies that promote autonomous motivations and perceived competence for behavioural changes in participants with the aim of improving weight maintenance following MCTIs.In light of stakeholder views in Study 2, Study 3A detailed a pilot study to test the efficacy of a maintenance intervention underpinned by Self Determination Theory (Deci & Ryan, 1985; 2000) and that integrated Motivational Interviewing (Miller & Rollnick, 1991; 2002) and cognitive behavioural strategies to improve the sustainability of behavioural and weight related outcomes following a MCTI. A secondary aim of Study 3A was to evaluate TF. Findings supported the potential importance of autonomous motivation and perceived competence in enhancing the maintenance of behavioural and weight related changes. Furthermore this study highlighted a need to explore participants' reasons for attrition from MCTIs. Study 3B provided a qualitative exploration of parents and children's reasons for attrition from MCTIs. Findings underlined the complexity of attrition with several psychological and motivational reasons appearing as the driving source for attrition. Study implications included the need to consider individual families' needs within MCTIs, targeting parents and children's motivations for maintaining a healthy lifestyle and weight differently. The collective implications of the four studies included the need for stakeholders to be involved at all levels of design, implementation and evaluation of MCTIs, the need to assess and report all aspects of TF and the need for MCTIs to develop families' perceived competence and autonomous motivations for health behaviour changes in order to improve the sustainability of weight related outcomes.