RT Journal Article SR Electronic T1 Investigating biographical post-bariatric surgery uncertainties in the light of changes in bodily practices: a mixed-method, multicentric and longitudinal research protocol JF BMJ Open JO BMJ Open FD British Medical Journal Publishing Group SP e101199 DO 10.1136/bmjopen-2025-101199 VO 15 IS 5 A1 Ferez, Sylvain A1 Bouchet-Mayer, Cyriac A1 Charissou-Pujol, Lise A1 Terral, Philippe A1 Couvry, Camille A1 Issanchou, Damien A1 Julien, Marie-Pierre A1 Perrin, Claire A1 Oppert, Jean-Michel A1 Ritz, Patrick A1 Disse, Emmanuel A1 YR 2025 UL http://bmjopen.bmj.com/content/15/5/e101199.abstract AB Introduction The effects of bariatric surgery have largely been studied from a medical viewpoint, seeking to measure changes in anthropometric, physiological or quality-of-life factors after the operation. Few studies, however, have focused on the dynamics of lifestyle changes. Yet we know that changing lifestyle habits—which are often part of the established social configurations at the origin of morbid obesity—is essential for a sustainable recovery from obesity. We also know that the major bodily transformations that occur in the six to twelve months following surgery produce a high degree of biographical uncertainty and affect social interactions. From a sociological perspective, the authors propose to study the processes of disruption and re-establishment of lifestyle habits in the first 24 months following bariatric surgery.Methods and analysis The ChiBarAPS study relies on a mixed-method longitudinal survey, comprising three components: qualitative, quantitative, literature and data review. It aims to document three main dimensions, which must be articulated to understand the dynamics of change: (1) the work undertaken by patients on themselves in order to identify and measure the evolutionary effects of surgery, as well as to adapt to them; (2) the experience of using pre- and post-surgery information and support systems, and evaluating their effects on the agency of the people who have undergone surgery; (3) the evolution of social participation and lifestyle habits. The qualitative component concerns a cohort of 30 patients, interviewed in depth (2 hours) on these three dimensions, 6 months, 12 months and 24 months after the operation. The quantitative part uses questionnaires applied to a second group of 200 patients, following the same timeline.Ethics and dissemination This study complies with reference methodology MR004 of the French National Data Protection Authority and was registered by the Data Protection Officer of the University of Montpellier on the activity registry of the institution (24 April 2024). Ethics approval has been obtained from the University of Montpellier ethics research board (n°UM2024-037). Informed consent will be obtained from all participants before data collection. The project has received funding from the French National Research Agency (n°ANR-23-CE41-0020-01) from February 2024 to the end of January 2028. The first results of the research will be disseminated from 2026 onwards to researchers, health professionals and patient support organisations. The results of the study will then be published in peer-reviewed scientific journals, both national and international.