Jinks, M. (2016). Regulating Eating through Acceptance and Commitment Therapy (REACT): a single case experimental design to evaluate a guided self-help intervention for individuals who are overweight or obese and engage in emotional eating (Doctoral dissertation, University of Lincoln).
Background: Obesity rates are growing globally along with the associated health and economic consequences (Caballero, 2007). However, weight loss is difficult, highlighting the need to address the psychological challenges of obesity (Wing & Phelan, 2005). Obesity is linked with emotional eating (Torres & Nowson, 2007). Therefore, interventions which may tackle emotional eating may address obesity. This study evaluated the effectiveness of an Acceptance and Commitment Therapy (ACT; Hayes, Strosahl & Wilson, 1999) intervention which has been considered helpful for this clinical problem. Method: Six participants engaged in a five week guided self-help ACT intervention. Utilising an AB single case experimental design (SCED) and follow-up, participants completed a range of implicit, explicit and behavioural assessments; targeting areas such as emotional eating, psychological ACT processes (referred to hereafter as ACT processes), Body Mass Index (BMI), and daily recordings of calorie intake and mood. Reliable and clinically significant changes were calculated on self-report measures. Simulation Modelling Analysis (SMA) examined the relationship between mood and calorie intake across baseline and intervention phases. Results: Half of the sample no longer met the criteria for “emotional eating” at follow-up. On the self-report measures, all participants “recovered”1 on at least one ACT-specific process, whilst two participants “recovered” from emotional eating. There was some evidence of temporal precedence whereby changes in the ACT processes occurred, prior to, or alongside, changes in emotional eating. SMA revealed a decrease in emotional eating in the intervention phase compared to the baseline phase for some participants. Inconsistencies were found between the implicit and explicit measures of emotional eating. Postintervention, four participants lost weight, three of whom maintained the weight loss at follow-up. All participants reported benefits from ACT. Discussion: Given the current obesity epidemic and the associated adverse consequences, finding an effective intervention for weight management is critical. This study resulted in four important findings; (a) ACT proved promising for some participants in reducing emotional eating and shifted the ACT process 1 Achieved both reliable and clinically significant change (Davies & Sheldon, 2011). 3 variables in a positive direction; (b) There was some evidence that ACT processes mediated changes in emotional eating. This has important theoretical implications as it indicates that mindfulness, defusion, values and acceptance influence emotional eating. Although theories have hypothesised this to be the case, this study provides empirical support. However, more single case research is required to demonstrate the replication of effect prior to refining weight management interventions; (c) Improvements in emotional eating measures did not reduce weight in all cases. This suggests that ACT alone, or in its current modality, may not be sufficient for behavioural change. It is suggested that more intensive input may be needed, or that ACT may make a useful adjunct to standard behavioural interventions. Nevertheless, in terms of cost-effectiveness, the brevity and modality of this intervention is a promising start, and (d) There were mixed findings regarding the impact of the intervention on the implicit emotional eating measure; correspondence with the explicit measure occurred for some participants. The utility of implicit measurement in targeting attitudes, behaviour or initial responses in this sample is questionable.