Background Body image concerns are prevalent among young adults, who may be vulnerable to developing body image concerns because of particular risk factors associated with this life period. With technological advancements, digital mobile health (mHealth) apps are cost-effective and scalable interventions. Thus, mHealth apps can be explored as a form of prevention effort to alleviate body image concerns in young adults. Objective In this randomized controlled trial, we examined the effectiveness of a self-guided mHealth app in improving body image and self-compassion in a sample of university students. Methods Participants (N=310) were randomized to a 9-day self-guided body image and self-compassion mHealth app (n=149) and to an active waitlist control group (n=161), where they completed a similarly structured 9-day program on cooperation. Both programs consisted of content learning and activities such as quizzes, with the number and length of activities matched for both programs. Measures were obtained at baseline, upon completion of the programs (after the intervention), and at 4-week follow-up. Results The intervention group for female participants reported significant reduction in body dissatisfaction (P<.001) and improvements in body appreciation (P<.001) and self-compassion (P=.001) compared with the active waitlist control group after the intervention. Similarly, for male participants after the intervention, a significant reduction was found in the intervention group in body dissatisfaction (P<.001) after the intervention as well as improvements in body appreciation (P=.02) and self-compassion (P=.047). The effects were maintained at 4-week follow-up for female participants on body dissatisfaction (P<.001), body appreciation (P<.001), and self-compassion (P=.02) but not for male participants. On body image risk factors, significant reductions were found for female participants after the intervention for thin-ideal internalization (P<.001), peer pressure (P=.002), and media pressure (P<.001) after the intervention, while the effects were only maintained for thin-ideal internalization (P=.008) and media pressure (P=.01) at 4-week follow-up, compared with the active waitlist control group. As for male participants, no intervention effects were found both after the intervention and at follow-up for all body image risk factors of muscularity internalization, peer pressure, and media pressure. Both apps were acceptable and participants engaged equally across the intervention and active waitlist control groups, as indicated on a measure of app engagement (P=.76). Conclusions This study provides preliminary evidence for a self-guided mHealth app in improving body image concerns and self-compassion in young adult university students. Future studies should include longer follow-ups, and examine its effects with the wider populations of young adults. Trial Registration ClinicalTrials.gov NCT04977973; https://clinicaltrials.gov/ct2/show/NCT04977973

BACKGROUND Body image concerns are prevalent among young adults and digital mobile health (mHealth) applications are cost-effective and scalable interventions. OBJECTIVE To examine the effectiveness of a mHealth application in improving body image and self-compassion in young adults METHODS This randomised controlled trial (RCT) examined the effectiveness of a self-guided mHealth application in improving body image and self-compassion in university students. Participants (N=310) were randomized to a body image and self-compassion 9-day self-guided mHealth application (N=149), and to an active-waitlist control group (N=161), where participants completed a similarly structured 9-day program with daily brief exercises on cooperation. RESULTS The intervention group reported significant reductions in body dissatisfaction, and improvements in body appreciation and self-compassion, as compared to the active wait-list control groups. Effects were maintained at 4-week follow-up for females, but not in males. Body image risk factors were also significantly reduced for females at post-intervention, and at 4-week follow-up, as compared to the active wait-list control group. CONCLUSIONS The current study provides preliminary evidence for a self-guided mHealth application in improving body image concerns in young adults. Future studies should include longer follow-ups, and examine its effects in the wider populations of young adults. CLINICALTRIAL This RCT was registered with ClinicalTrials.gov (Registration number: NCT04977973).