Beyond weight: a stigma-free, integrated approach to obesity in patients affected by cancer

Obesity affects a substantial proportion of patients receiving cancer treatment and shapes prognosis, treatment tolerance, and survivorship outcomes. The longstanding reliance on body mass index has shaped a weight-centric paradigm that misses the metabolic and functional phenotypes behind clinical risk, and too often delivers care driven by weight stigma rather than by physiology.

This framework paper reconsiders the management of obesity in patients affected by cancer along three interconnected lines: assessment beyond BMI, stigma-free communication, and integrated, phase-sensitive care along the cancer continuum. Key content. Body composition phenotyping, including the recognition of sarcopenic obesity, ectopic fat deposition, and myosteatosis, is now within reach through opportunistic radiomics on staging computed tomography, and yields prognostic information that BMI alone cannot deliver. International consensus statements increasingly frame obesity as a chronic, complex, and relapsing disease rather than a matter of individual responsibility, and emphasize that person-first language and the active reduction of weight bias should be embedded as core components of cancer care. The therapeutic armamentarium spans nutritional strategies grounded in ESPEN principles, structured exercise with resistance training at its core, behavioural and psychological support, GLP-1 receptor agonists, and metabolic-bariatric surgery, the latter linked to substantial reductions in cancer incidence and mortality. Goals shift along the continuum: lean mass optimisation in prehabilitation, lean mass preservation during active treatment, fat mass reduction in follow-up, and cachexia prevention in palliative phases.

A phase-sensitive, multidisciplinary, stigma-free framework moves obesity care away from a weight-centric paradigm and toward optimisation of body composition and metabolic health throughout the cancer trajectory.