Rosenkranz et al. BMC Public Health 2010, 10:81 http://www.biomedcentral.com/1471-2458/10/81 mediators of behavior change, or perhaps the impacted mediators failed to result in detectable behavior change. Future studies of this sort should assess additional med- iating variables such as skills, attitudes, intentions, and especially self efficacy for behaviors that impact obesity. More than a decade ago, Cullen and co-authors con- ducted a nutrition education intervention in Girl Scout troops of similar age to the present study’s sample [11]. Cullen found significant increases in FV consumption among the intervention troop scouts, and suggested that troop positive norms and social support could be created by consistently serving FV at troop meetings, which may lead to increased consumption of FV in scouts. Although we did not assess troop meeting environmental norms, per se, it appears that our intervention policies created a troop positive snack norm of having FV that nearly all the girls ate each time. Also, the healthful eating promotion efforts of the troop leaders could constitute social support, but we did not assess whether other girls were supportive of FV consumption. We were unable to detect positive outcomes on habitual consumption levels in our interven- tion troop girls, but better measures combined with a greater focus on FV, may have shown more favorable results. Similar to our approach, Baranowski and collea- gues also used a customized badge incentive with Boy Scouts, and were able to increase FV consumption in their intervention [9,10]. On the PA side, intervention troop leaders provided girls with opportunities to be physically active at troop meetings, and accelerometer-based data show that the girls took advantage of those opportunities by being less sedentary and getting more MVPA than control girls. However, our data suggest that this bi-monthly troop meeting PA had no impact on girls’ self-reported habi- tual PA levels. Similarly, Ievers-Landis and colleagues implemented an intervention to increase weight bearing PA (and calcium intake) in Girl Scouts, with a goal of primary prevention of osteoporosis [22]. The results of their study showed no significant differences in PA among two intervention groups and a control group. Future studies of such interventions may benefit by bet- ter measures, such as use of accelerometer-based mea- sures of habitual PA. The present study held a number of limitations, including a relatively small sample studied over only a five-month period. Our study’s size and scope were lim- ited based on constraints in funding. Despite the size, we believe the high participation rate, combined with extensive multiple observations, all bode well for the external validity of the findings within our geographic region. We relied on several self-report measures for both parents and children, and some measures may have limited reliability and validity. Similar studies in the future could be strongly improved with better Page 11 of 13 measures of behavioral influences on obesity. In contrast to these limitations, our direct observation of troop environments and rigorous objective measurement of PA in troop meetings and child weight status provide major strengths for this study. Conclusions In conclusion, the Healthier Troops in a SNAP interven- tion was implemented with good fidelity, and resulted in greater health promoting opportunities, MVPA, and healthful eating in troop meetings, but no discernable impact on the behavioral influences of obesity in chil- dren and parents outside of troop meetings. Implement- ing a health-promotion curriculum and supporting policies to provide more healthful environments in Girl Scouts troop meetings appears feasible on a broader scale. Fully powered intervention studies with additional measures of mediating variables will extend the work presented here. Improved approaches or coordinated interventions across environments may be needed to extend health promotion beyond scout meeting settings, if lasting behavior change and obesity prevention remain targeted outcomes. Abbreviations BMI: body mass index; CON: control troop; FV: fruits and vegetables; HE: healthful eating; INT: intervention troop; MVPA: moderate to vigorous physical activity; PA: physical activity; SSB: sugar-sweetened beverages; TV: television. Acknowledgements The authors would like to thank all the troop leaders and participants for taking part, and Beth Larue and Kim Savidge for their assistance with data collection. Funding for this project was provided, in part, by the Sunflower Foundation: Health Care for Kansans, a Topeka-based philanthropic organization with the mission to serve as a catalyst for improving the health of Kansans. Author details 1Department of Human Nutrition, Kansas State University, Manhattan, KS, USA. 2Youth Health Behavior Research Laboratory, Kansas State University, Manhattan, KS, USA. 3Department of Health Sciences, Univ. of Colorado, Colorado Springs, CO, USA. 4Department of Kinesiology, Kansas State University, Manhattan, KS, USA. Authors’ contributions RR and DD conceived of the study. RR designed the SNAP intervention, oversaw data collection and analysis, and wrote first draft of the manuscript. DD and TB contributed to data analysis and revised manuscript drafts. All authors read and approved the final manuscript. Competing interests The authors declare that they have no competing interests. Received: 17 August 2009 Accepted: 19 February 2010 Published: 19 February 2010 References 1. Baskin ML, Ard J, Franklin F, Allison DB: Prevalence of obesity in the United States. Obes Rev 2005, 6(1):5-7. 2. Ogden CL, Carroll MD, Flegal KM: High body mass index for age among US children and adolescents, 2003-2006. JAMA 2008, 299(20):2401.