Abstract: | It is well known that significant others (particularly romantic partners) can influence people’s weight management efforts. However, what constitutes effective support—and from which type of individual (e.g., romantic partner, family member, friend)—is unclear. Thus, framed by confirmation theory, we assessed the effectiveness and types of communication of a weight-loss “buddy” through reports of 704 individuals enrolled in a 15-week synchronous online weight-loss program. Roughly 54% of participants chose buddies; and those who did lost more weight and waist inches than those who were involved in the program without buddy support. We also found that a combination of high accepting and high challenging messages from buddies was associated with the greatest decrease in body mass index (BMI) as well as the greatest reduction in waist size. Furthermore, the support by romantic partners paralleled support by other types of buddies. Having a supportive buddy who was not a romantic partner was just as effective as turning to a romantic partner for assistance. This study underscores the important role of a buddy in supporting weight-loss program involvement and encourages individuals to consider enlisting the help of a buddy, as opposed to losing weight alone, in order to maximize weight management effectiveness. |