Cognitive remediation therapy plus behavioural weight loss compared to behavioural weight loss alone for obesity: study protocol for a randomised controlled trial.

BACKGROUND: Current research indicates that obese individuals have cognitive deficits in executive function, leading to difficulties with planning, impulse control and decision-making. High levels of inflammation have been proposed to contribute to executive function deficits in individuals with obesity.

METHODS/DESIGN: One hundred and seventy-six obese participants will be randomly assigned to one of two groups: (1) behavioural weight loss alone (BWL) group = 8 sessions of individual BWL sessions plus 12 group BWL sessions or (2) Cognitive Remediation Therapy for Obesity (CRT-O) plus BWL group (CRT-O + BWL) = 8 sessions of individual CRT-O plus 12 group BWL sessions. The study is double blind - participants will only be told that two weight-loss treatments are being compared and research assistants conducting outcome assessments will not know participants' group allocation. Blood tests will be conducted to measure inflammatory markers. Measurement points will be at baseline, post treatment and 1-year follow-up. The primary outcomes will be differences between treatment groups in percentage weight loss, executive function, binge eating and an examination of whether changes in executive function predict changes in weight and binge eating. Secondary outcome measures will examine changes on inflammation, quality of life, and grazing behaviour and whether these predict changes in executive function and weight.

DISCUSSION: If CRT-O + BWL is more effective in assisting people to lose weight long term than BWL alone it should significantly improve treatment outcomes. This study expands upon our recent trial which showed that CRT-O enhanced executive function and weight loss in obese adults. The current study is strengthened by several factors: it is double-blind, it uses an active control, has a larger sample size, and measures inflammation to examine the mechanisms.

TRIAL REGISTRATION: The RCT is registered with the Australian New Zealand Registry of Clinical Trial, trial identifier: ACTRN12616000658415 . Registered on 20 May 2016.