Many recent reviews of the literature concerning behavioral treatments of obesity have concluded that behavioral methods have not been as successful in treating this problem as might have been predicted in the early years of behavior modification. Among the many potential reasons for this lack of success is the growing trend to utilize group statistical designs rather than single subject designs to examine the problem of obesity, in spite of the fact that single case methodology has provided the foundation for applied behavior analysis and behavior therapy. Several behavioral journals were surveyed to determine more precisely the trends in types of research strategies utilized in obesity studies. The potential relationship between research methodology and the development of effective treatments is discussed.