Dietary Management of IgE-Mediated and Non-IgE-Mediated Food Allergies: A Systematic Review of Current Evidence and Clinical Implications

Background: Food allergy is an increasing global health problem associated with substantial clinical, nutritional, and psychosocial burden. Methods: This systematic review was conducted according to the PRISMA 2020 Statement. PubMed/MEDLINE and Scopus were systematically searched for studies published between January 2016 and December 2025. A total of 218 records were identified, of which 180 were screened after duplicate removal; 14 studies met the predefined eligibility criteria and were included in the qualitative synthesis. Methodological quality was assessed using validated appraisal tools according to study design, and findings were synthesized narratively following the SWIM guideline. Results: Avoidance of confirmed culprit foods remains a central component of food allergy management, although prolonged or unnecessarily restrictive elimination may adversely affect dietary diversity, nutritional adequacy, growth, and quality of life, particularly in children and patients with multiple food allergies. Randomized controlled trials and systematic reviews support early allergen introduction for prevention of IgE-mediated food allergies and oral immunotherapy as an active treatment option in selected patients with IgE-mediated food allergies, although treatment-related adverse events remain an important consideration. In contrast, evidence supporting several dietary management strategies for non-IgE-mediated food allergies is more frequently derived from observational studies and evidence-based recommendations, highlighting important gaps in the current evidence base. Conclusions: Current evidence supports individualized dietary management based on regular reassessment, nutritional monitoring, supervised food reintroduction when clinically appropriate, and multidisciplinary care. The evidence supporting different dietary strategies remains heterogeneous, particularly for non-IgE-mediated food allergies, emphasizing the need for further high-quality research.