Overweight and obesity prevalence among Cree youth of Eeyou Istchee according to three body mass index classification systems

Background: Little is known about the suitability of three commonly used body mass index (BMI) classification systems for Indigenous youth. We estimated overweight and obesity prevalence among Cree youth of Eeyou Istchee according to three BMI classification systems, assessed the level of agreement between them, and evaluated their accuracy through body fat and cardiometabolic risk factors. Methods: Data on 288 youth (aged 8-17 years) were collected. Overweight and obesity prevalence were estimated with Centers for Disease Control and Prevention (CDC), International Obesity Task Force (IOTF) and World Health Organization (WHO) criteria. Agreement was measured with weighted kappa (kappa w). Associations with body fat and cardiometabolic risk factors were evaluated by analysis of variance. Results: Obesity prevalence was 42.7% with IOTF, 47.2% with CDC, and 49.3% with WHO criteria. Agreement was almost perfect between IOTF and CDC (kappa w = 0.93), IOTF and WHO (kappa w = 0.91), and WHO and CDC (kappa w = 0.94). Means of body fat and cardiometabolic risk factors were significantly higher (P-trend < 0.001) from normal weight to obesity, regardless of the system used. Youth considered overweight by IOTF but obese by CDC or WHO exhibited less severe clinical obesity. Conclusions: IOTF seems to be more accurate in identifying obesity in Cree youth.