Although the term "behavioral epidemiology" has been used in the literature since the late 1970s, it has not been clearly defined. A behavioral epidemiology framework is proposed to specify a systematic sequence of studies on health-related behaviors, leading to evidence-based interventions directed at populations. The phase are: 1--establish links between behaviors and health; 2--develop measures of the behavior; 3--identify influences on the behavior; 4--evaluate interventions to change the behavior; 5--translate research into practice. Mature research areas are expected to have more studies in the latter phases. Recent volumes of four journals (Annals of Behavioral Medicine, Health Psychology, Journal of Nutrition Education, Tobacco Control) were audited, and empirical studies were classified into these phases. Phase 3 studies were common (identifying influences on behaviors; 27% to 50%), and Phase 2 studies were least common (measurement; 0% to 15%). Annals of Behavioral Medicine and Health Psychology were low on Phase 4 (intervention studies; 9% and 11%, respectively). The Journal of Nutrition Education was the only journal reviewed that had a substantial number (20%) of Phase 5 studies (translating research into practice). The behavioral epidemiology framework can be used to evaluate the status of research on health behaviors and to guide research policies.