Objectives: We estimated the prevalence of overweight and obesity in Cree Canadian children aged 5 years (n=1044) using international and US growth references and examined the longitudinal tracking of weight categories between ages 2 and 5 years (n=562).
Methods: Weight categories based on body mass index (calculated from measured heights and weights) were derived from the International Obesity Task Force (IOTF) and the Centers for Disease Control and Prevention (CDC) references.
Results: According to the IOTF reference, 52.9% of children were overweight (31.6%) or obese (21.3%) whereas with the CDC reference, 64.9% were overweight (27.5%) or obese (37.4%). The IOTF and CDC references provided dissimilar tracking of weight categories. Based on the IOTF reference, 4.9% of the children who were normal weight at age 2 years were obese at age 5 years. Based on the CDC reference, 14.9% of children categorized as normal weight at age 2 years were obese at age 5 years.
Conclusions: The IOTF reference provided more conservative estimates of obesity than the CDC reference, and longitudinal analyses showed dissimilar tracking of weight categories with the 2 references. Public health responses to obesity prevalence estimates should be made with awareness of methodological limitations.