Bct and Theory use in Interventions Targeting Initiation and Maintenance of Weight Loss – Systematic Review
Background: Behavioural interventions produce weight loss, but weight loss maintenance is elusive. The correspondence between behaviour change techniques (BCTs) used to initiate and maintain weight loss and the effect of theory use on weight loss maintenance is currently unknown. Methods: Systematic review of interventions inducing weight loss (?5% body weight) in obese adults followed by randomisation to different maintenance treatments reporting weight outcomes ?12 months. BCTs were compared for weight loss vs. maintenance phases, and associations between theory and weight maintenance effects were examined. Findings: 45 RCTs met inclusion criteria, including 9451 participants (BMI=35.2). Most studies employed the same BCTs targeting initiation and maintenance. Instruction provision, self-monitoring and problem solving were the most frequently employed BCTs. Theory based interventions were more effective compared to non-theory based ones [-2.3kg 95%CI -3.2 to -1.5 vs. -0.1 95%CI -1.2 to 0.9, P<.001). Discussion: There is a lack of differentiation between BCTs used for initiation and maintenance of weight loss. Theory based maintenance interventions were found to be more effective.