The Clinical Obesity Maintenance Model (COMM) and the efficacy of cognitive remediation therapy in obesity

Abstract

This thesis consists of two studies. In Study 1, in the light of recent evidence in the fields of neuropsychology and obesity, particularly on the deficits in the executive function in overweight and obese individuals, a conceptual and theoretical framework of obesity maintenance is introduced by way of a Clinical Obesity Maintenance Model (COMM). The COMM argues that psychological variables, that of habit, cluster behaviours, emotion dysregulation, mood and health literacy interact with executive functioning and impact on the overeating/binge eating behaviours of obese individuals. A cross-sectional study aimed to evaluate the COMM and explore correlates of and possible risk factors for sedentary behaviours, binge eating and grazing that are hall mark features of obesity. A total of 100 participants, ranging in age from 18 to 55 years were recruited. Data were collected on neurocognitive outcomes and psychological self-report measures. The major predictions of the COMM were tested using multiple linear regression analyses to examine the relationships between health literacy, executive function, mood, emotion regulation, unhealthy eating and sedentary habits and a cluster (co-occurrence) of unhealthy eating and sedentary behaviours with obesity maintaining behaviours, i.e., binge eating, grazing and sedentary behaviours. Findings suggested that poor health literacy is an important risk factor for adverse behaviours that maintain obesity and that mood, emotion regulation skills, unhealthy eating and sedentary habits and a cluster of unhealthy eating and sedentary behaviours may influence this relationship. Results of the current study did not support the presence of an association between neurocognitive outcomes in executive function and obesity maintaining behaviours. Health literacy interventions that target beliefs and attitudes about obesity maintaining behaviours along with treatments that address mood, emotion regulation skills and overcoming unhelpful habits may be particularly vital in order to mitigate the chronic nature of obesity. Study 2 of this research progamme tested the efficacy of a novel manualised cognitive remediation therapy (CRT-O) for adult obesity, designed to address executive deficits in obesity, enhance reflective practice and aid weight loss and maintenance. A randomized controlled trial (registered at the Australian New Zealand Clinical Trials Registry (ANZCTR: 12613000537752) was conducted. 80 obese adults (body mass index >30 kg/m2 ) in the community received three weekly sessions of a group Behaviour Weight Loss Treatment (BWLT), and then were randomised either to receive CRT-O or to enter a no-treatment control group. Measurement points were at baseline, post CRT-O (or 4 to 6 weeks after BWLT for the no-treatment control) and 3 months post treatment. The primary outcomes were performance in measures of executive function. Secondary outcomes were participants' weight change in percentage, body mass index, hip to waist ratio, eating behaviours and health related quality of life (HRQoL). Longitudinal linear mixed effects modeling revealed a significant interaction between the stated outcomes and the CRT-O treatment over time. Results suggest better outcomes in all of the variables except depression for the treatment group compared with the control group. Future studies with larger samples and longer follow-up periods are needed to inform further developments of CRT-O including its use as an adjunctive therapy in weight loss treatments. ACCESS RESTRICTED TO ABSTRACT ONLY UNTIL 28 JUNE 2021

Date of Award	2015
Original language	English