Objective: This meta-analysis evaluated the types of lifestyle treatments used in published obesity drug studies and assessed their contribution to weight losses associated with pharmacological interventions.
Research methods and procedures: Randomized, placebo-controlled, double-blind clinical trials of anti-obesity agents that are/were Food and Drug Administration-approved for the treatment of obesity (both prescription and over-the-counter), and drugs that are Food and Drug Administration-approved and are used off-label for obesity were included. Studies were located by computer searches of databases (e.g., Medline, PsychInfo) and reviewing tables of content/reference sections of journals, abstracts, previous reviews, past empirical studies, relevant book chapters, and recent issues of journals that regularly publish obesity research. In addition, a number of individuals who regularly publish in the obesity literature were asked to provide personal lists of obesity-drug studies. Based on the above criteria, a total of 108 randomized clinical trials were located.
Results: Balanced-deficit diets, low-calorie diets, and self-monitoring were the most used lifestyle treatments in published obesity studies. They were incorporated into 40.7%, 25%, and 23.1% of pharmacotherapy studies, respectively. Physical activity and other behavioral or psychotherapeutic interventions rarely were used. A substantial portion of weight loss experienced by patients was attributable to both "placebo effects" and to the lifestyle treatments.
Discussion: Obesity-pharmacotherapy trials do not use lifestyle treatments with the frequency expected based on the official positions of most professional organizations concerned with the comprehensive management of obesity.