This paper reviews issues regarding dietary adherence. Issues and barriers unique to dietary adherence, in contrast to adherence to physical activity or medication regimens, are discussed. These include decision making, social and cultural contexts, perceptions and preferences, and environmental barriers. We review factors known to increase adherence in dietary interventions, including education, motivation, behavioral skills, new and modified foods, and supportive interactions. We conclude with directions for future study, such as improved measurement of diet-related behavior and longitudinal, culturally sensitive interventions.