Overweight / obesity among youth has recently been declared a "public health crisis" in the United States and other Western countries due to its alarming increase in prevalence (Flegal, 1999; Kohn \& Booth, 2003; Lobstein et al., 2004; Sokol, 2000). Over the past decade, overweight in youth (Body mass index \[BMI\] \> 95th percentile) has increased 4% for school-age children, 6 - 11 years old. Adolescents, 12 - 19 years of age are even more overweight (5%) (Ogden et al., 2002). Further, American adolescents had the highest prevalence of overweight among 15 western countries included in a cross-sectional, nationally representative school-based study (Lissau et al., 2004). Such trends are particularly troubling given the psychosocial and physical health risks associated with being overweight in childhood (Must \& Strauss, 1999). Overweight among youth appears to confer longer-term health risks even among later normative weight adults (Must et al., 1992). Further, both longer-term health risks and the probability of adult obesity is greater for overweight adolescents than for those developing weight problems earlier in childhood (Must et al., 1992; Whitaker et al., 1997). Collectively, these factors suggest adolescent weight control is an important public health priority.
Clinic-based weight control treatments for youth have demonstrated some success, however, most empirically-supported interventions have been designed for younger school-age children and their families (see Epstein et al., 1998 for a review). Even though a large volume of research explores adult-weight control (see NIH-NHLBI, 1998 for a review) and (though more limited) substantial research examines childhood obesity (see Epstein et al., 1998 for a review), obesity treatments for adolescents have not been adequately studied. Furthermore, almost all empirically tested weight control interventions among youth have been based in academic research clinics rather than the primary care medical settings, in which weight problems among these youth are most often identified and, arguably, in which they could be most efficiently treated. Placing adolescent weight-related interventions within primary medical care settings could make such interventions both more cost-effective and easier to disseminate. The purpose of this study is to assess the feasibility, acceptability, relative cost, and efficacy of a collaborative primary care-based behavioral lifestyle intervention (Enriched Intervention - EI) for overweight adolescent females and their families. This multi-component intervention, adapted for gender and developmental stage, will include a combination of assessment, group teen and parent sessions, individual telephone-based coaching contact, and a distinct collaborative care component with follow-up visits to the youth's primary care provider \[PCP\]. Further, we will compare the EI to a low intensity intervention \[LII\] (assessment and information about healthy diet and activity, and follow-up visits with the youth's PCP) and a usual care control condition.
We hypothesize that:
1. Adolescents participating in the Enriched Intervention (EI) will have a greater decrease in BMI percentile scores than adolescents receiving the Low Intensity Intervention (LII) or Usual Care.
2. Adolescent in EI will have improved healthy lifestyle skills (e.g., more physical activity, less junk food and sodas) compared with those receiving LII or Usual Care.
3. Adolescents in EI will report higher psychosocial functioning and quality of life outcomes than those receiving LII or Usual Care.
4. Neither intervention will result in increases in problematic eating or weight-related behaviors or beliefs.
