American Indian youth have the highest prevalence of obesity of all ethnic groups in the U.S. Obese individuals are at higher risk for cardiovascular disease, high blood pressure, dyslipidemia, type 2 diabetes mellitus and stroke. Reducing childhood obesity will require effective prevention strategies that focus on environments and promotion of physical activity and a healthy diet.
Objective: To understand trends in the prevalence of obesity and severe obesity among American Indian tribal youth during the past 20 years.
Methods: Participants included American Indian boys and girls aged 10-15 years from 14 different tribes in the Southwest, primarily Arizona, who attended a 1-week residential summer wellness camp from 1995 to 2015. Height and weight were measured on the first day of camp; sex- and age-specific body mass index (BMI) percentile and BMI z-score were computed using CDC SAS code. Obesity in childhood is defined by age- and sex-specific BMI percentile greater than or equal to the 95th percentile; severe obesity is defined as BMI ≥ 120% of the 95th percentile of BMI-for-age or as BMI ≥ 35.0 kg/m2. Chi-square tests and two-sample t-tests were used to determine the effects of sex and time on obesity and severe obesity. The significance threshold was set at p < .05.
Results: Our sample was comprised of 354 youth, 154 males (43.5%) and 200 females (56.5%), aged 12.7 ± 1.6 years (mean ± SD). Across the 20-year period, the prevalence of obesity was 80.2% (284 of 354) overall, and was greater in males (85.7%; 132 of 154) than females (76.0%; 152 of 200, p = 0.02). Likewise, the prevalence of severe obesity was greater in males (65.6%; 101 of 154) than females (50.0%; 100 of 200, p = 0.003) and was 56.8% (201 of 354) overall. The mean BMI-for-age percentile and z-score were 94.5 ± 11.9 and 2.05 ± 0.71, respectively; BMI z-score was higher in males (2.17 ± 0.7) than in females (1.96 ± 0.7, p = 0.004). There were no clear trends in obesity among our American Indian youth campers from 1995 to 2015, but the prevalence was high in all years (range 62.5 - 95.0%; 10 of 16 youth in 2011 - 19 of 20 youth in 2003).
Conclusions: Throughout the 20-year period, there was consistently a high prevalence of obesity and severe obesity among American Indian tribal youth. Boys displayed a higher prevalence and severity of obesity relative to girls. Given the strong association between obesity in youth and the risk for chronic disease, our results underscore the critical need to intervene early in regards to establishing healthy eating and exercise behaviors among American Indian youth.