Physiological pathways of weight stigma: a scoping review of biomarker evidence and methodological challenges

The social devaluation of individuals based on body weight, commonly known as ‘weight stigma’ is a pervasive psychosocial stressor linked to detrimental mental and physical health outcomes (1) . In Aotearoa New Zealand, where 1 in 3 adults live with obesity (2) , weight-based discrimination may affect up to 40% of this population (3) . Beyond psychosocial consequences, emerging evidence indicates that weight stigma can activate biological stress pathways, contributing to chronic disease risk independently of body weight. This review aimed to critically synthesise studies linking ‘weight stigma’ and ‘physiological biomarkers’ (cardiovascular, HPA axis, inflammation, metabolic) to map evidence, evaluate methodological strengths/limitations, and identify mechanistic priorities for future research. Systematic searches of PubMed, PsycINFO (Ovid), and Scopus (up to May 2025) identified 23 eligible studies (11 cross-sectional, six longitudinal, six experimental) among 288 in the initial search. Most acute stress studies reported elevated cortisol and cardiovascular reactivity (e.g., increased blood pressure, heart rate) following stigma exposure. Limited longitudinal evidence suggested associations with chronic low-grade inflammation (e.g., elevated C-reactive protein). However, findings were constrained by heterogeneous measures and the overrepresentation of U.S.-based, Caucasian women with a BMI ≥ 25, limiting generalisability. Theoretical approaches have largely drawn from the allostatic load and biopsychosocial models, with growing application of the Cyclic Obesity/Weight-Based Stigma (COBWEBS) model (4) , which conceptualises weight stigma as a chronic stressor that initiates behavioural, emotional, and physiological feedback loops leading to further weight gain and stigma. While these models provide valuable insight into mechanisms of stress and dysregulation, few studies have examined how such cycles manifest within culturally diverse or non-Western contexts. Pacific peoples in Aotearoa experience disproportionate burdens of both obesity and discrimination yet remain virtually absent from biomarker-based stigma research. To address this gap, the next phase of research will employ a feasibility mixed-methods study integrating quantitative biomarker assessments (cortisol, hs-CRP, blood pressure, heart rate) with qualitative Talanoa (a Pacific indigenous methodology) sessions among New Zealand European and Pacific males. This culturally grounded approach will contextualise how lived experiences of stigma may translate into physiological dysregulation, aligning with the COBWEBS framework and extending it to underrepresented populations. Ultimately, this work will lay the groundwork for more equitable health research and practice in Aotearoa New Zealand.