Objectives : Human support can boost weight reduction in Internet-based weight-loss intervention. However, the most effective way to combine human support and the Internet for weight loss is unclear. This study aimed to examine the effects of two weight-loss programs for male workers aged 18-39 that combined different intensities of human support with website support compared to a delayed-intervention group (control group; CG), in a randomized controlled trial.

Methods : Seventy-one participants with overweight or obesity were allocated to one of three 12-week treatment programs. The Standard Support Group (SSG) was provided support via website and two face-to-face group guidance sessions, at the beginning and at the end of the program along with monthly general emails throughout the program. The Enhanced Support Group (ESG) received four remote support sessions based on Supportive Accountability (SA) in addition to the SSG. The CG was provided the same program as SSG after the other two groups had completed the program. The primary outcome was body weight reduction.

Results : ESG participants reduced their weight significantly more than SSG and CG participants ( P = 0.038, P < 0.001, respectively), and SSG participants reduced their weight significantly more than CG participants ( P = 0.033).

Conclusions : The additional remote human support provided to the participants in the ESG was beneficial for weight loss in male workers. The low-intensity program provided to the SSG was also effective. Further studies with more participants in diverse settings and with participants who are less interested in their health and weight management are needed.