UK Healthcare Professionals’ Knowledge, Attitudes, and Beliefs About Adult Obesity: A Qualitative Study

Background: Healthcare professionals' knowledge, attitudes, and beliefs toward adults living with obesity influence clinical engagement, communication, and quality of care. However, existing outcome measurement instruments used to assess these constructs have demonstrated limitations in development quality, contextual relevance, and content validity, particularly within the United Kingdom (UK) healthcare system. Objective: To conduct a qualitative concept elicitation study aligned with the Consensus-based Standards for the Selection of Health Measurement Instruments (COSMIN) recommendations to identify key themes shaping UK healthcare professionals' knowledge, attitudes, and beliefs regarding adults living with obesity in order to inform the development of an outcome measurement instrument. Design: Qualitative descriptive study using semi-structured group and individual interviews. Methods: 35 UK healthcare professionals from multiple disciplines participated in semi-structured individual and group interviews. Data were analysed using inductive reflexive thematic analysis in accordance with COSMIN recommendations for content validity and item generation. Results: Four interrelated themes were identified: (1) clinical working environment, (2) knowledge of obesity, (3) attitudes to obesity, and (4) beliefs about professional roles. The clinical working environment was identified as a primary contextual determinant influencing how knowledge is constructed, how attitudes are expressed, and how beliefs about professional roles are enacted in practice. Structural constraints, organizational culture, role ambiguity, and service limitations influenced clinicians' confidence, communication, and perceived legitimacy in adult obesity care. Conclusion: Healthcare professionals' knowledge, attitudes, and beliefs regarding adult obesity are not solely individual attributes but are embedded within organizational and service contexts. These findings provide a strong empirical foundation for COSMIN-aligned item development and support the creation of a context-sensitive outcome measurement instrument to inform research, workforce development, and service improvement in UK adult obesity care. Patient or Public Contribution: Patient and Public Involvement (PPI) contributors reviewed the interview guide to ensure clarity and relevance prior to data collection.