Outcomes of a culturally informed weight-loss competition for New Zealand Indigenous and Pacific peoples: a quasi-experimental trial.

Background: Reducing obesity prevalence among marginalised subgroups with disproportionately high obesity rates is challenging. Given the promise of incentives and group-based programmes we trialled a culturally tailored, team-based weight-loss competition with New Zealand Māori (Indigenous) and Pacific Island people.

Methods: A quasi-experimental 12-months trial was designed. The intervention consisted of three six-months competitions, each with seven teams of seven members. Eligible participants were aged 16 years and older, with a BMI ≥30 kg/m and being at risk of or already diagnosed with type-2 diabetes or cardiovascular disease. Height, weight and waist circumference were measured at baseline, 6 and 12 months.

Results: Recruitment of a control group (n = 29) versus the intervention (n = 132) was poor and retention rates were low (52 and 27% of intervention participants were followed-up at six and 12 months, respectively). Thus, analysis of the primary outcome of individual percentage weight loss was restricted to the 6-months follow-up data. Although not significant, the intervention group appeared to lose more weight than the control group, in both the intention to treat and complete-case analyses.

Conclusions: The intervention promoted some behaviour change in eating behaviours, and a resulting trend toward a reduction in waist circumference.

Trial Registration: ACTRN12617000871347 Registered 15/6/2017 Retrospectively registered.