Obesity, defined by a body mass index (BMI) ≥ 30 kg/m2, affects more than 31% of American adults. Additionally, nearly one-quarter of U.S. adults meet criteria for the metabolic syndrome, a clustering of clinical signs (i.e., elevated waist circumference, blood pressure, glucose or triglycerides, decreased HDL cholesterol) that is associated with increased risk of cardiovascular death. Behavior modification programs and pharmacologic interventions for obesity typically result in an 8% to 10% loss of initial body weight. Losses of this magnitude are associated with clinically significant improvements in metabolic parameters among obese persons. The availability of traditional behavioral weight control programs, however, is limited as many of these programs are based in academic medical centers. Furthermore, pharmacotherapy is seldom covered by third-party payers. Thus, there are concerns about the accessibility of these interventions to the many obese individuals who could benefit from weight loss.
The purpose of the study is to improve the management of obesity in primary care practice, where obesity is commonly encountered but infrequently addressed. Three hundred and ninety persons at 6 primary care practices within the University of Pennsylvania Health System will be randomized to one of three 2-year interventions: Usual Care, Brief Lifestyle Counseling, or Enhanced Brief Lifestyle Counseling. After training in obesity management and intervention strategies, each site will enroll approximately 65 individuals with a BMI of 30-50 kg/m2 plus two or more components of the metabolic syndrome. Participants in the Usual Care condition (N=130) will receive educational materials plus quarterly visits with a primary care provider (PCP). Those in the Brief Lifestyle Counseling condition (N=130) will receive the same PCP visits, plus 26 brief counseling sessions with an auxiliary health care provider (e.g., a medical assistant), on-site or by phone. Participants in the Enhanced Brief Lifestyle Counseling condition (N=130) will additionally receive the same treatment as those in the Brief Lifestyle Counseling group, plus the choice of adjunctive meal replacements or pharmacotherapy.
Two-year changes in weight will be compared across groups. Participants who receive the Brief Lifestyle Counseling and the Enhanced Brief Lifestyle Counseling interventions are predicted to achieve greater weight loss than those who receive Usual Care. A secondary hypothesis is that participants in Enhanced Brief Lifestyle Counseling condition will lose significantly more weight at month 24 than participants in the Brief Lifestyle Counseling group. Secondary analysis will also compare changes in the metabolic syndrome (and its individual components), mood, quality of life, dietary intake, eating behavior, appetite, physical activity and sexual function, as well as cost-effectiveness, among the three conditions. Intervention protocols and study results will be disseminated to other health care providers and payers.
