Diverse cultural components of behavior may have significant impacts on patterns of eating, drinking, and social interaction, irrespective of socioeconomic status. For example, the major world religions prescribe or proscribe specific dietary behaviors; some of these are rooted in historical or geographical origins as well as group folklore; and they have integral roles as expressions of religious piety and group cohesiveness. The literature is replete with ecological observations of between-country differences in disease trends, some of which have been associated with dietary practices. The study of distinct cultural and religious groups (especially migrants acculturating to new environments) and the extent to which they adhere to culturally-based dietary precepts, has advanced our knowledge of psychosocial influences on food habits, nutritional adequacy, and overall health. However, a relatively small proportion of culturally-based research studies conducted to date have explored cross-cultural, ethnic, or religious variables. This paper reviews some population-based differences in dietary habits and other behaviors by ethnocultural group or religious denomination; health consequences and suggestions for future research are discussed.