Objectives: This study aimed to determine whether a mobile health (mhealth) intervention is effective in reducing weight and changing dietary behavior among employees with overweight and obesity. The study also investigated whether engagement with the intervention affected its effectiveness. Methods: The intervention involved the use of a dietary coaching app, a wearable device for monitoring physical activity and body composition, and a messenger app for communicating with participants and an intervention manager. A total of 235 employees were recruited for a 12-week intervention from eight workplaces in Korea. Questionnaire surveys, anthropometric measurements, and 24-h dietary recalls were conducted at baseline and after the intervention. Results: After the intervention, significant decreases in the mean body weight, body mass index, body fat percentage, and waist circumference were observed. Furthermore, the consumption frequencies of multigrain rice and legumes significantly increased, whereas those of pork belly, instant noodles, processed meat, carbonated beverages, and fast food significantly decreased compared with those at baseline. The mean dietary intake of energy and most nutrients also decreased after the intervention. When the participants were categorized into three groups according to their engagement level, significant differences in anthropometric data, dietary behaviors, and energy intake were observed following the intervention, although there were no differences at baseline, indicating that higher engagement level led to greater improvements in weight loss and dietary behavior. Conclusions The intervention had positive effects on weight loss and dietary behavior changes, particularly among employees with higher engagement levels. These results indicate the importance of increasing the level of engagement in the intervention to enhance its effectiveness. The mhealth intervention is a promising model for health promotion for busy workers with limited time.

Objectives: A mobile health intervention program was provided for employees with overweight and obesity for 12 weeks, and a process evaluation was completed at the end of the program. We investigated participant engagement based on app usage data, and whether engagement was associated with the degree of satisfaction with the program. Methods: The program involved the use of a dietary coaching app and a wearable device for monitoring physical activity and body composition. A total of 235 employees participated in the program. App usage data were collected from a mobile platform, and a questionnaire survey on process evaluation and needs assessment was conducted during the post-test. Results: The engagement level of the participants decreased over time. Participants in their 40s, high school graduates or lower education, and manufacturing workers showed higher engagement than other age groups, college graduates, and office workers, respectively. The overall satisfaction score was 3.6 out of 5. When participants were categorized into three groups according to their engagement level, the upper group was more satisfied than the lower group. A total of 71.5% of participants answered that they wanted to rejoin or recommend the program, and 71.9% answered that the program was helpful in improving their dietary habits. The most helpful components in the program were diet records and a 1:1 chat with the dietary coach from the dietary coaching app. The barriers to improving dietary habits included company dinners, special occasions, lack of time, and eating out. The workplace dietary management programs were recognized as necessary with a need score of 3.9 out of 5. Conclusions Participants were generally satisfied with the mobile health intervention program, particularly highly engaged participants. Feedback from a dietary coach was an important factor in increasing satisfaction.