Giorgia Varallo,1 Carlos Suso-Ribera,2 Ada Ghiggia,3 Marco Veneruso,4 Roberto Cattivelli,5 Anna Guerrini Usubini,6,7 Christian Franceschini,1 Alessandro Musetti,8 Giuseppe Plazzi,9,10 Jacopo Maria Fontana,11 Paolo Capodaglio,11,12 Gianluca Castelnuovo6,7 1Department of Medicine and Surgery, University of Parma, Parma, 43121, Italy; 2Department of Basic and Clinical Psychology and Psychobiology, Jaume I University, Castellon de la Plana, 12071, Spain; 3Department of Life Sciences, University of Trieste, Trieste, 34127, Italy; 4Department of Neurosciences, Rehabilitation, Ophthalmology, Genetics, Maternal and Child Health (DINOGMI), University of Genoa, Genoa, Italy; 5Department of Psychology, University of Bologna, Bologna, 40127, Italy; 6Department of Psychology, Catholic University of Milan, Milan, 20123, Italy; 7Istituto Auxologico Italiano IRCCS, Psychology Research Laboratory, San Giuseppe Hospital, Verbania, 28824, Italy; 8Department of Humanities, Social Sciences and Cultural Industries, University of Parma, Parma, 43125, Italy; 9Department of Biomedical, Metabolic and Neural Sciences, University of Modena and Reggio Emilia, Modena, 41125, Italy; 10IRCCS Istituto delle Scienze Neurologiche di Bologna (ISNB), Bologna, 40139, Italy; 11Istituto Auxologico Italiano IRCCS, Orthopaedic Rehabilitation Unit and Research Laboratory in Biomechanics and Rehabilitation, San Giuseppe Hospital, Verbania, 28824, Italy; 12Department of Surgical Sciences, Physical and Rehabilitation Medicine, University of Turin, Turin, 10121, ItalyCorrespondence: Jacopo Maria Fontana, San Giuseppe Hospital, Strada Cadorna 90, Verbania, 28824, Italy, Tel +39 0323 514 331, Email j.fontana@auxologico.itPurpose: Individuals with fibromyalgia and obesity experience significant impairment in physical functioning. Pain catastrophizing, kinesiophobia, and pain acceptance have all been identified as important factors associated with the level of disability. The objective of this study was to evaluate the role of pain catastrophizing, kinesiophobia, and pain acceptance as mediators of the association between perceived pain severity and physical functioning in individuals with fibromyalgia and obesity.Patients and Methods: In this cross-sectional study, 165 women with fibromyalgia and obesity completed self-report questionnaires of perceived pain severity (ie, Numeric Pain Rating Scale), pain catastrophizing (ie, Pain Catastrophizing Scale), kinesiophobia (ie Tampa Scale of Kinesiophobia), pain acceptance (ie, Chronic Pain Acceptance Questionnaire), and perceived physical functioning (ie, Physical Functioning subscale of the Fibromyalgia Impact Questionnaire). In addition, a performance-based test (ie, 6-minute walking test) was conducted to assess objective physical functioning. Two multiple mediation analyses were performed.Results: Pain acceptance and kinesiophobia mediated the relationship between pain severity and self-reported physical functioning. Pain catastrophizing and kinesiophobia mediated the relationship between pain severity and performance-based functioning.Conclusion: Pain acceptance, kinesiophobia, and pain catastrophizing should be addressed in rehabilitative intervention to improve physical functioning. Interestingly, the subjective and objective aspects of physical functioning are influenced by different factors. Therefore, interventions for women with fibromyalgia and obesity should focus on factors related to both subjective and performance-based physical functioning.Keywords: chronic pain, fear-avoidance model, fibromyalgia, functioning, obesity, psychological flexibility model