Parental and Healthcare Professional Experiences of Food Allergen Introduction During Complementary Feeding: A Behavioural Theory-Informed Systematic Review.

BACKGROUND: IgE-mediated food allergy burdens individuals, families and healthcare systems. Randomised controlled trials indicate early introduction and regular consumption of common food allergens in infancy can reduce food allergy risk. Few studies have explored parental and healthcare professional experiences. This systematic review examines their perspectives applying a theory-informed behavioural analysis identifying key barriers influencing food allergen introduction. METHOD: A systematic search of seven databases was conducted in November 2025. All study designs and published primary research papers were included and screened against the inclusion/exclusion criteria. Quantitative findings were summarised narratively and analysed alongside qualitative data. All findings were synthesised concurrently using an integrated thematic synthesis following the Thomas and Harden approach. Quality appraisal was assessed. RESULTS: Twenty-five studies were included. Four themes were identified: (1) Practical barriers to introducing the allergenic foods, (2) perceived risk and fear of allergic reactions and safety, (3) navigating and making sense of food allergy prevention information, particularly conflicting advice for parents and (4) food allergy prevention advice, guidance awareness, interpretation and implementation. CONCLUSION: Effective food allergy prevention requires early, consistent support for parents from suitably trained healthcare professionals. Advice should be evidence-based, simple, culturally relevant and accessible, promoting realistic and healthy infant and family foods and diets.