The Royal Commission into Aged Care Quality and Safety identified numerous issues around food provision in aged care, including high rates of malnutrition, the need for increased choice and person-centered care, and poor nutritional knowledge among staff1. Prior intervention that increased provision of high-protein, high-calcium foods to residents in aged care was associated with reduced rates of falls, fractures, malnutrition and weight loss2. Intervention was through food service where staff were supported to incorporate these foods into their menus based on the needs and preferences of residents and foodservice capacity. To upscale this program, we developed a Bone Health Training Program to educate and empower food service staff to develop menus in line with learnings from the intervention. This study applies the Theoretical Domains Framework (TDF) to identify barriers and enablers for implementing menu changes over the 12-week intervention. Qualitative data was collected from 11 chefs, 11 food service managers, 6 food service staff and 7 care staff from 11 aged care homes. This consisted of questionnaires and focus group sessions pre- and post-implementation, post- 1-on-1 interviews and field observation notes collected by research staff during intervention. All data were coded and analysed using a TDF-informed matrix that consists of 14 domains, allowing for a holistic assessment of behavioural influences to guide development of targeted interventions. The Environmental Context and Resources domain emerged as the most significant barrier to implementation due to physical infrastructure limitations such as inadequate kitchen facilities and equipment, poor staffing levels, time pressures and budget constraints. The Knowledge and Skills domain revealed gaps in understanding of protein requirements for older adults and limited skills in modifying recipes to enhance nutritional quality. The transformation of professional identity emerged as a central theme across multiple domains. Food service staff who expanded their professional identity from solely food preparers to contributors to the nutritional care of residents were significantly more motivated to implement and sustain evidence-based practices. Moreover, positive reinforcement from residents, management support, and peer collaboration emerged as key enablers. Effective interventions must develop knowledge and skills in staff, create supportive organisational environments and address system-level barriers. Mandatory nutrition-related training should be provided to upskill staff and highlight their contribution to resident care. The training should include fostering skills in peer collaboration and communication as well as resident engagement. Other considerations could include kitchen upgrades, equipment purchases, staffing adjustments, and policy changes that support evidence-based practice.