Implementation intentions for weight loss in college students with overweight and obesity: a proof-of-concept randomized controlled trial

One in three college students have overweight or obesity and are in need of brief, simple weight loss interventions. Implementation intentions, a strategy that connects a goal-aligned behavior to a cue, facilitate goal attainment of health behaviors but have not been applied as a standalone treatment for weight loss. The purpose of this study was to examine the efficacy of an implementation intention weight loss intervention in college students. In this three-arm, proof-of-concept, randomized controlled trial, college students with overweight/obesity (N = 95) were randomized to one of three conditions: an implementation intention group (IMP), an enhanced implementation intention group (IMP+) that included text message reminders and fluency training (i.e., training for speed and accuracy), and a control goal intention group (GOL) for 4 weeks. Participants completed anthropometric and self-report assessments pretreatment and posttreatment and experience-sampling assessments during the study to assess how implementation intentions contribute to behavior change. Across the sample, IMP and IMP+ groups reported significantly more goal-congruent behaviors than the GOL group. However, no between-condition differences emerged for weight and diet outcomes. Across conditions, students lost a statistically significant amount of weight, improved diet quality, and reduced caloric intake (ps < .05). Setting implementation intentions was associated with increased behaviors consistent with weight loss goals. Moreover, participants in all groups lost a statistically significant amount of weight. Incorporating implementation intentions into weight loss interventions, and testing the efficacy of this approach on weight loss over a longer duration, may be beneficial for college students with overweight/obesity.