Rugby Fans in Training New Zealand (RUFIT-NZ): protocol for a randomized controlled trial to assess the effectiveness and cost-effectiveness of a healthy lifestyle program for overweight men delivered through professional rugby clubs in New Zealand

Background A healthy lifestyle program that appeals to, and supports, obese New Zealand (NZ) European, Māori (indigenous) and Pasifika men to achieve weight loss is urgently needed. In Scotland, Football Fans in Training (FFIT), a weight management and healthy lifestyle program for overweight and obese men aged 35–65 years , delivered by community coaching staff at professional football clubs, has been shown to be beneficial and cost-effective. A pilot program inspired by FFIT but delivered by professional rugby clubs in NZ (n = 96) was shown to be effective in weight loss, improved physiological outcomes, and adherence to healthy lifestyle behaviors in overweight and obese men. The objective of this trial is to determine the effectiveness and cost-effectiveness of the Rugby Fans in Training New Zealand (RUFIT-NZ) program. Methods A pragmatic, two-arm, multi-center, randomized controlled trial involving 308 overweight and obese men aged 30–65 years, randomized to either an intervention group (n = 154) or a wait-list control group (n = 154). The intervention-group participated in the 12-week RUFIT-NZ program, a gender-sensitized, healthy lifestyle intervention adapted to the environment and cultural diversity of NZ and delivered through professional rugby clubs. Participants in the intervention group undergo physical training sessions, in addition to workshop-based sessions to learn about nutrition, physical activity, sleep, sedentary behavior, and a range of behavior-change strategies for sustaining a healthier lifestyle. The control group receives the program after 52 weeks. The primary outcome is change in body weight from baseline to 52 weeks. Secondary outcomes include change in body weight at 12 weeks; waist circumference, blood pressure, fitness, and lifestyle behaviors at 12 and 52 weeks; and cost-effectiveness. A process evaluation informed by the RE-AIM framework will evaluate potential implementation of RUFIT-NZ as an ongoing program in NZ after the trial. Discussion This trial will investigate the effectiveness and cost-effectiveness of the RUFIT-NZ program in overweight and obese NZ men