BACKGROUND:

Primary care is a promising setting for childhood obesity prevention, in addition to other settings, such as the family, schools, and the community. Unfortunately, most pediatric primary care providers are not trained to deliver behavior modification interventions and, according to preliminary data, are less likely to address obesity prevention when they perceive insufficient time during well-care visits.

DESIGN NARRATIVE:

This is a controlled trial of obesity prevention, with group randomization at the practice level, of two standardized 12-month intervention strategies, based on the Behavioral Economics theory, and delivered by primary care providers after training in behavior modification. The first strategy will target change in multiple behaviors, while the other will target one behavior (beverage consumption). These two interventions will be compared to an active control intervention unrelated to weight (accident prevention). Eight primary care practices will be randomized to each arm with 21 subjects per practice, for a total of 24 practices and 504 subjects. The primary aim is to demonstrate that either obesity prevention intervention will result in less BMI increase (adjusted using z-score) in children age 8 to 12 years at risk for overweight (BMI 85th-95th percentile), compared to a control intervention, at the end of the intervention. The study also hypothesizes that, in this context, the multiple-behavior intervention, the single-behavior intervention, or both will result in less adjusted BMI increase than the control intervention at 24 months post-randomization, with no a priori assumption in differences between the two obesity prevention strategies. Blood pressure, insulin resistance, dyslipidemia, and oral health status will be secondary outcomes. Intermediate behavioral outcomes and process data will be collected.

Inclusion criteria: Male and female patients, ages 8.0 to 12.9 years, will be eligible to participate in the study if they have sought care at the participating practices at least once in the past three years. These patients will not necessary be a patient of the physician participating in the study, but will be familiar with the practice environment and staff. In these practices, most patients are familiar with more than one pediatrician, as providers cover for one another for emergency and during vacations and holidays. Children "at risk for overweight" at their last clinical visit, according to the Center for Disease Control and Prevention (CDC) definition of a BMI at or above the 85th percentile, but less than the 95th percentile, will be eligible. In order for the single-behavior intervention to be meaningful, the study sample will be restricted to children who consume at least 28 oz of sweetened beverages per week, i.e. an average of 4 oz per day, as assessed during the telephone screening by selected components of a validated food frequency questionnaire.

Exclusion criteria: Children considered by their primary care physician to have any of the following conditions will be excluded from the study: developmental delay requiring special education, depression, psychosis, eating disorders, significant orthopedic problems interfering with physical activity, diabetes, or any other significant chronic condition potentially interfering with nutrition or physical activity. Children treated with a drug known to affect weight gain will also be excluded. The following conditions will be acceptable if they have been well controlled in the past 3 months: hypertension, dyslipidemia, sleep apnea, asthma, and insulin resistance without diabetes. Subjects who have a measured BMI z-score at the first visit higher than +2.0 SD (97.7th percentile) will also be excluded, as they require treatment rather than prevention. Families who are uninterested or unable to participate to the intervention will be excluded from the study

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