1 Department of Family Practice, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
2 School of Kinesiology, Faculty of Education, University of British Columbia, Vancouver, BC, Canada.
3 Centre for Studies in Family Medicine, Department of Family Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
4 The Bone and Joint Institute, Western University, London, ON, Canada.
5 Department of Health, Kinesiology, and Applied Physiology, Faculty of Arts and Science, Concordia University, Montréal, QB, Canada.
6 Department of Physical Therapy, Faculty of Medicine, University of British Columbia, Vancouver, BC, Canada.
7 School of Physical Therapy, Faculty of Health Sciences, Western University, London, ON, Canada.
8 School of Health Studies, Faculty of Health Sciences, Western University, London, ON, Canada.
9 Department of Epidemiology and Biostatistics, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
10 Department of Medicine, Schulich School of Medicine & Dentistry, Western University, London, ON, Canada.
11 Department of Clinical Medicine and Surgery, University of Naples Federico II, Naples, Italy.

Background: Obesity disproportionately impacts men's health yet fewer men engage in preventive healthcare. We examined the effectiveness of Hockey Fans in Training (Hockey FIT), a gender-sensitised lifestyle intervention that engages men with overweight/obesity through their passion as fans of a local sports team, on weight change and other health indicators.

Methods: Pragmatic, cluster randomised trial (aged 35-65 years, body mass index = 27 kg/m²) within 42 community-based sites in Canada and the United States, randomly assigned (1:1) to intervention (Hockey FIT) or control (wait-list) and stratified by region. Sites were selected based on partnerships with local major junior/professional hockey teams and community implementation partners. Intervention participants received exercise and education during a three-month active phase (once-weekly, 90-min sessions) followed by a nine-month minimally-supported phase; control participants continued with usual activities. Primary outcome was weight change at 12 months. Assessment teams were blinded to group assignment including photos of weight measurements on digital scales, to provide proof of values recorded (post COVID-19). Analyses followed intent-to-treat. Trial registration: ClinicalTrials.gov, NCT03636282.

Findings: Between November 13, 2018-November 12, 2021, 20 sites (n = 497) were allocated to intervention and 22 sites (n = 500) to control. Participants with baseline weight and weight at 3 or 12 months, were included in the primary analysis (20 intervention sites [n = 354]; 22 control sites [n = 425]). At 12 months, mean weight change was -2.02 kg (95% confidence interval [CI], -2.78 to -1.26) with intervention and -0.92 kg (CI, -1.58 to -0.26) with control (difference, -1.10 kg [CI, -2.11 to -0.09], p = 0.03). There were 22 non-study related serious adverse events (45.5% in intervention; 54.5% in control).

Interpretation: Hockey FIT reduced weight in men with overweight or obesity. Hockey FIT is an innovative approach to engage men at increased risk of non-communicable disease in effective health behaviour change, through their passion as fans of their local hockey team.

Funding: Public Health Agency of Canada; Canadian Institutes of Health Research.