Behavioral and pharmacologic treatment of obesity

An estimated 61% of the United States population is currently overweight (>25 kg/m2) or obese (>30 kg/m2) and therefore at risk for numerous medical conditions, including type II diabetes, dyslipidemia, and hypertension. Behavioral treatment (BMOD) produces medically meaningful weight losses (about 10% of initial body weight) that are maintained, with continued treatment, for up to one year. Unfortunately, in the year after treatment, patients regain about one third of their initial weight loss, and 3-5 years after treatment most patients have regained back to their initial weight. Pharmacotherapy has been proposed as a means for improving the long-term maintenance of weight loss. The anti-obesity agent Sibutramine (SIB), a noradrenegeric and serotonergic reuptake inhibitor, that promotes average short and long-term weight losses that are significantly greater (3-5 kg) than placebo. Surprisingly, the mechanism through which SIB works to promote weight loss is unclear. In addition, the effect of SIB in combination with BMOD has not been investigated. Therefore, the purpose of this study was to compare the effects of SIB, BMOD, and SIB plus BMOD on several behavioral variables, including appetite, behavioral adherence, restraint, and self-efficacy over the course of an 18-week randomized clinical trial. Participants were 69 obese (BMI = 37.5 k/m2) males (23.2%) and females (76.8%) with an average age of 45.1 years. Participants were predominately Caucasian (73.9%) and college educated (82%). Results indicated that SIB was associated with initial reductions in hunger and craving. Behavior therapy resulted in increased adherence to weight control behaviors, such as exercise and self-monitoring. Combined, the two treatments appeared to have complementary effects on appetite and behavior. This study is the first to examine the independent effects of SIB, BMOD, and their combination on behavioral variables. Future research is needed to examine the role of hunger and craving in weight loss as well as the types and intensities of lifestyle interventions needed to maximize the effects of SIB. In addition, researchers know little about how best to sequence medication and BMOD; medication may be most useful as a maintenance or rescue strategy after treatment with BMOD. Furthermore, whether there are subgroups of the obese population who respond best to pharmacologic or behavioral treatments awaits future research. Ultimately, understanding the optimal means of combining lifestyle and drug therapies is critical to practitioners in both behavioral and primary care settings.