Abstract

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).
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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.