Background Childhood onset obesity and related health consequences continue to be major clinical and public health issues in the USA and abroad. Schools provide an opportunity to implement prevention strategies to large, diverse pediatric audiences. Healthier Options for Public Schoolchildren (HOPS) was a school-based obesity prevention intervention with nutrition and physical activity components implemented in the elementary school setting targeting 6–13 year olds.

Methods HOPS was a quasi-experimental elementary school-based obesity prevention intervention targeting ethnically diverse 6–13-year-olds (Kindergarten-6^th). Over four school years (August 2004-June 2009), five schools (four intervention; one control, N=3,183, 48% Hispanic) in Florida participated in the study. Waist circumference (WC) data was reported in the Fall of 2005 and Spring of 2006 only and these one year results are reported here.

Results Among boys, the mean incremental change in WC (measured in centimeters [cm]) increase was significantly less in the intervention (1.35 cm +/- 0.88 [SD]) versus control schools (3.83 cm +/- 0.94) (P<0.0001). Among girls the mean incremental change in WC increase was significantly less in the intervention (1.20 cm +/- 0.84) versus control schools (4.17cm +/- 0.89) (P<0.0001). Similarly, waist-to-height ratio results showed that the intervention group mean incremental change was significantly less versus the control group for boys (P=0.0002) and girls (P<0.0001).

Conclusions Elevated WC is strongly correlated with cardiometabolic disease risk factors and should be monitored in young children as such. School-based obesity prevention interventions show promise in improving weight and potentially cardiometabolic health in elementary-school aged children.