The moderating and mediating role of eating behaviour traits in acceptance and commitment therapy-based weight management interventions: protocol for an individual participant data meta-analysis
BMJ Open 2023 ; 13: e076411.
Kudlek L, Mueller J, Eustachio Colombo P, Sharp SJ, Griffin SJ, Ahern AL
DOI : 10.1136/bmjopen-2023-076411
PubMed ID : 38081662
PMCID : PMC10729174
URL : https://doi.org/10.1136/bmjopen-2023-076411
Abstract
Introduction: Precision medicine approaches to obesity aim to maximise treatment effectiveness by matching weight management interventions (WMIs) to characteristics of individuals, such as eating behaviour traits (EBTs). Acceptance and commitment therapy (ACT)-based WMIs may address EBTs such as emotional and uncontrolled eating more effectively than standard interventions, and might be most effective in people with high levels of these traits. However, few studies have examined this directly. We will examine (a) whether ACT-based interventions are more effective for people with certain levels of EBTs (ie, moderation) and (b) whether ACT-based interventions operate through changes in EBTs (ie, mediation).
Methods and analysis: This individual participant data (IPD) meta-analysis will follow the Preferred Reporting Items for Systematic Reviews and Meta-Analyses of Individual Participant Data guidance. We will include studies on ACT-based WMIs that assessed EBTs in people with a body mass index ≥25 kg/m2. We identified studies by screening studies included in a previous review of third wave cognitive behavioural interventions, and updating the search to 20 June 2022. We will request IPD from eligible published and unpublished studies. We will harmonise and re-analyse data using a two-stage random effects meta-analysis pooling within-trial interactions to investigate moderating effects and using a one-stage simultaneous equation model to examine mediating effects. We will assess the risk of bias in included studies using the Cochrane Risk of Bias tool 2 and the Risk of Bias in Non-randomised Studies of Interventions tool.
Ethics and dissemination: Ethical approval has been obtained from the Cambridge Psychology Research Ethics Committee (Application No: PRE.2023.121). Data sharing will follow data transfer agreements and coauthorship will be offered to investigators contributing data. Findings will be disseminated through peer-reviewed journals and conferences and will contribute to the lead author's PhD thesis.
Lay Summary
What do we know already? Weight management programmes can help people lose weight, but they don’t work equally well for everyone. This might be because people have different tendencies that influence what and how much they eat. These tendencies are called eating behaviour traits. For example, eating behaviour traits describe how someone responds to emotions or cravings when it comes to food (emotional eating), and whether they tend to eat in a controlled or impulsive manner (restraint or uncontrolled eating). Unlike many other weight management programs, those based on Acceptance and Commitment Therapy specifically aim to help with eating behaviour traits like emotional and uncontrolled eating. These programmes focus on teaching people to recognise and accept difficult thoughts and feelings, such as food cravings.
What will we be studying? In this project, we are aiming to examine the role of eating behaviour traits in programmes that use Acceptance and Commitment Therapy more closely. Our project will be guided by two questions:
(1) Do weight management programmes that use Acceptance and Commitment Therapy work better for people who often struggle with certain eating behaviour traits, such as eating due to negative emotions, compared to people who don’t?
(2) Do weight management programmes that use Acceptance and Commitment Therapy help with weight loss by improving peoples’ eating behaviour traits?
How will we do this? We will search for studies that have collected relevant data on people participating in weight management programmes that use Acceptance and Commitment Therapy. We will ask authors of these studies to share their data with us, so that we can combine it into one database for analysis.
Why will it matter? Answering these questions may help researchers and healthcare practitioners to match weight management programmes to individuals’ eating behaviour traits and help make programmes more effective.