Changes in self-rated health, quality of life, and psychological flexibility among adults with overweight over a 24-month acceptance and commitment therapy–based lifestyle intervention

This study investigated the impact of online psychological flexibility training and support provided by peers on self-rated health (SRH) and health-related quality of life (HRQoL) among adults with overweight. It was a secondary analysis of a single-arm multi-center intervention study that was conducted in a real-life context. In a 2-years acceptance and commitment therapy (ACT) lifestyle intervention, participants (N = 177) engaged in online ACT activities while receiving support from trained peers. Participants completed surveys at baseline, 6, 12, and 24 months. The research data were analyzed with structural equation modelling. At baseline, the participants with high SRH (n = 83) had higher psychological flexibility and HRQoL than did participants with low SRH (n = 94). At 24 months, the participants with low SRH at baseline reported increases in SRH, vitality and depression dimensions of HRQoL, and psychological flexibility. Increased psychological flexibility was associated with improved SRH.