Factors influencing adherence to dietary management in patients with classical galactosemia: A systematic review

Lifelong dietary restriction is the main approach to managing classical galactosemia, yet maintaining adherence is challenging and poorly understood. Existing research has focused primarily on metabolic outcomes, with limited synthesis of the behavioral, psychosocial, and healthcare system factors shaping long-term dietary management. This systematic review aimed to identify determinants of dietary adherence in individuals with classical galactosemia and to synthesize these factors using the socio-ecological model to provide a multi-level understanding of influences on adherence. A systematic search of PubMed, Scopus, Web of Science, and Embase was conducted following PRISMA guidelines. Studies examining factors related to dietary management in classical galactosemia were included. Extracted determinants were synthesized narratively and deductively mapped to individual, interpersonal, healthcare system, community, and structural levels of the socio-ecological framework. Study quality was assessed using the JBI critical appraisal tool. Evidence directly examining adherence determinants was limited. However, psychosocial and contextual findings revealed consistent multi-level influences. Individual factors included psychological burden and cognitive challenges; interpersonal influences involved caregiver involvement and family dynamics; healthcare-level determinants related to access to specialist metabolic care and variability in dietary guidance; community factors included barriers to social participation; and structural concerns reflected long-term dependency and support needs. These findings suggest that dietary adherence in classical galactosemia is shaped by interacting ecological influences rather than solely individual behavior. Addressing psychosocial burden, family support, healthcare system consistency, and social participation barriers may be critical for improving long-term dietary management. The scarcity of adherence-focused research highlights the need for theory-informed, multi-level intervention studies in this rare metabolic disorder.