The impact of acceptance and commitment therapy (ACT) on the psychological defense mechanism and weight loss program: A randomized controlled trial among university students during COVID-19 movement control order

Abstract

This study examined the effectiveness of acceptance and commitment therapy (ACT) in changing the psychological defense mechanism and promoting weight loss among overweight or obese (OW/OB) university students. A sample of 152 OW/OB university students who reported high immature and neurotic defense styles was randomly assigned into ACT, ACT-EX (ACT and structured exercise program), or a control group (CG) for a six-week intervention program. Group × time interactions showed that the BMI and all defense styles improved in the ACT and ACT-EX groups. The BMI was significantly lower in ACT-EX than in ACT, while the within-group effect size was larger in ACT than in ACT-EX for immature and neurotic defense styles. The mature defense style showed a significant improvement albeit with a small effect size in both ACT and ACT-EX. Both ACT interventions were found to be effective in promoting weight loss and improving the psychological defense mechanism, including experiential avoidance.