ABSTRACT: BACKGROUND:Quality, evidence-based obesity management training for family medicine residents is needed to better support patients. To address this gap, we developed a comprehensive course based on the 5As of Obesity Management™ (ASK, ASSESS, ADVISE, AGREE, ASSIST), a framework and suite of resources to improve residents' knowledge and confidence in obesity counselling. This study assessed the course's impact on residents' attitudes, beliefs, and confidence with obesity counselling. METHODS:The course combines lectures with a bariatric empathy suit experience, standardized and in-clinic patient practice, and narrative reflections. Using a multi-methods design we measured changes in 42 residents' attitudes, beliefs, and self-confidence and thematically analyzed the narrative reflections to understand residents' experience with the course content and pedagogy. RESULTS:Following the course, residents reported improved attitudes towards people living with obesity and improved confidence for obesity counselling. Pre/post improvement in BAOP scores (n = 32) were significant (p < .001)., ATOP scores did not change significantly. Residents showed improvement in assessing root causes of weight gain (p < .01), advising patients on treatment options (p < .05), agreeing with patients on health outcomes (p < .05), assisting patients in addressing their barriers (p < .05), counseling patients on weight gain during pregnancy, (p < .05), counseling patients on depression and anxiety (p < .01), counseling patients on iatrogenic causes of weight gain (p < .01), counseling patients who have children with obesity (p < .05), and referring patients to interdisciplinary providers for care (p < .05). Qualitative analysis of narrative reflections illustrates that experiential learning was crucial in increasing residents' ability to empathically engage with patients and to critically reflect on implications for their practice. CONCLUSION:The 5AsT-MD course has the potential to increase residents' confidence and competency in obesity prevention and management. Findings reflect the utility of the 5As to improve residents' confidence and competency in obesity management counselling.