Biopsychosocial Model

biopsychosocial (adj.) — A framework, formalized by George L. Engel in 1977, in which health, illness, and behavior are understood as arising from the dynamic, bidirectional interaction of biological, psychological, and social factors, rather than from any single domain in isolation (Engel, 1977). In nutritional psychology, it names the foundational assumption that the Diet–Mental Health Relationship (DMHR) cannot be reduced to nutrient biochemistry alone: every dietary intake pattern operates simultaneously as biology (nutrients, microbiota, neurotransmission), psychology (cognition, affect, eating behavior, body image), and social context (culture, family, food environment, policy). CNP’s framing extends this classical trio by explicitly including environmental pathways alongside the biological, psychological, and social (CNP).