BACKGROUND: Obesity has reached epidemic proportions nationwide among children, adolescents, and adults and is considered one of the most serious health problems facing Americans today. Disparities in overweight and obesity prevalence exist, with higher prevalence among ethnic minority groups and those with a lower family income. American Indian children and adults are among those with the highest rates of obesity and related diseases. Young American Indians have high rates of type 2 diabetes, and the rates appears to be increasing substantially. Obesity in American Indian children has serious implications for their immediate and long-term health. Unless this trend is reversed, American Indian populations will be burdened by an unprecedented increase in the incidence of chronic diseases, such as type 2 diabetes and cardiovascular disease.

The high prevalence of obesity among American Indian children and the associated health and financial burdens warrant strong and effective prevention efforts. While the prevention of childhood obesity has risen to the top of the list of public health priorities, relatively little research has focused on childhood obesity prevention, especially for high-risk populations. The development and evaluation of innovative, culturally appropriate, and effective strategies to prevent excessive weight gain is critical, particularly for American Indian youth. Early prevention efforts are especially important given the substantial evidence that eating and physical activity habits are established in early childhood and track into adulthood. Adopting healthy eating and physical activity habits early in life is a promising means of preventing obesity and related diseases. The best intervention to prevent obesity in children should target the two most prominent influences on the young child''''s eating and physical activity behaviors: the school and the family. Further, obesity in American Indian children begins very early in life suggesting that interventions need to begin early. The study is conducted at Pine Ridge and Rosebud reservations, two Lakota reservations in South Dakota. Data show that 43% of American Indian 5-6 year olds in South Dakota are already overweight. Thus, targeting children in this young age group may be efficacious.

DESIGN NARRATIVE: The study design is a group-randomized controlled trial with 14 schools randomized to two conditions: 7 schools will be randomly assigned to the intervention condition and 7 schools to the control condition. Randomization will occur after baseline measures have been completed. The focus of the intervention, Ohiyu lyojanjan - Bright Start Program, is to create dietary and physical activity environmental change at school and home.The intervention will focus on two cohorts of kindergarten children (n=500), and follow them through the end of 1st grade. The intervention length will be 16 months. There will be 4 schools on the Rosebud reservation and 10 schools on the Pine Ridge reservation assigned to two cohorts. The two cohorts will begin the study one year apart; the first cohort will have baseline measures in the fall of 2005 and begin the intervention in January 2006, and the second cohort will have baseline measures in fall of 2006 and begin the intervention in January 2007. This staggered design will allow for more contact with participating schools and families by key intervention staff, increased monitoring and control of the intervention within schools, and decreased staff costs. Overview of control and intervention conditions. The intervention will focus on changing the school and home environments related to physical activity and food. The school physical activity environmental intervention component will incorporate 60 minutes of active physical activity at school daily for K-1 st graders through a combination of physical education classes, a classroom walking program, in-class activity breaks, and active morning and afternoon recess. The school food environment intervention will focus on improving school meals (breakfast and lunch), classroom snacks, and teacher classroom food practices. The intervention will target the school food service to decrease availability of high-fat/sugar foods, regulate portion control of foods served, and increase fruits (not juice) and vegetables served. The family intervention will address the household food and physical activity environment and family dietary and physical activity behaviors. Because parents of kindergarten children in the selected schools will be recruited for participation prior to the randomization of schools, it may be problematic to engage all parents without providing anything to those who are assigned to the control condition. To foster parent interest in study participation, parents in the control condition will be mailed monthly newsletters with general family recommendations for prevention of excess weight gain.

The major hypothesis is that by the end of the 16-month intervention, children in the intervention schools, relative to children in the control schools, will have significantly lower body mass index (BMI) and percent body fat after adjustment for baseline values. The primary outcome measures in children are BMI and percent body fat. Secondary measures include child''''s total daily physical activity, nutrient and food-group analysis of school meals and snacks, and assessment of classroom food and physical activity practices. Child measures will occur at the beginning of kindergarten (baseline), at the end of kindergarten (BMI only), and at the end of the 1st grade. Parents will be surveyed at baseline, and when their child is at the end of the 1st grade. Parent assessments will include measures of household food availability, parent reports of their own and child eating and physical activity behaviors.