1. ^*Department of Nutrition, University of North Carolina, Chapel Hill, North Carolina
2. ^†Department of Epidemiology, University of North Carolina, Chapel Hill, North Carolina
3. ^‡Department of Epidemiology, The Ohio State University, Columbus, Ohio

Correspondence: June Stevens Department of Nutrition, CB 7461, University of North Carolina, Chapel Hill, NC 27599. E-mail: June_Stevens@unc.edu

^*The costs of publication of this article were defrayed, in part, by the payment of page charges. This article must, therefore, be hereby marked "advertisement" in accordance with 18 U.S.C. Section 1734 solely to indicate this fact.

Received 12 December 2006; Revised  000; Accepted 12 February 2007.

Abstract

Because randomized controlled trial designs are used more frequently to evaluate obesity prevention programs, nuances in the methodology used for this application become apparent. Areas of attention are the selection of outcome measures with high validity, attention to the description of the intervention, the use of analyses that match the sampling design, and dealing with loss to follow-up. We recommend increased use of preliminary or evidentiary research designed to develop and test intervention components and hypothesized mediators before fully powered, randomized, obesity prevention trials are attempted. Both randomized and observational designs can be used for the purpose. Attention to design issues will ultimately lead to more successful, cost-effective randomized trials, and more rapid movement toward efficacious and effective obesity prevention programs.