Attitudes, stigma and knowledge on obesity in Mexico: a national cross-sectional survey of the general population and healthcare professionals living with or without obesity.

Background: Weight stigma has major health impacts but remains understudied in Latin America. This study explores attitudes, stigma and knowledge of obesity in Mexican healthcare professionals (HCPs) and the general population (GenPop) living or not with overweight/obesity. Methods: A national cross-sectional, anonymous, online survey was conducted among 3859 adults (1262 GenPop and 2597 HCPs). Participants completed sociodemographic questions, three validated instruments assessing stigma, beliefs, and internalized bias, 12 items evaluating obesity knowledge and treatment perceptions, and 14 items addressing medical care experiences and weight stigma among GenPop. Four groups were created based on body mass index (BMI): GenPop and HCPs living with overweight or obesity (GenPop/OW-OB and HCPs/OW-OB, BMI ≥25 kg/m Findings: Stigma and beliefs varied significantly across groups. HCPs/NOW-OB reported the highest weight stigma scores, while GenPop/OW-OB showed the highest weight bias internalization and HCPs/OW-OB scored highest on beliefs that obesity is outside of individual control. Internalization was higher in women and decreased with age. Less than 30% define obesity as a disease, and even so, stigmatizing and outdated responses related to weight loss, weight regain, and the treatment of severe obesity were demonstrated. Personal experiences revealed that 79% of GenPop/OW-OB avoided medical visits, with over half feeling judged by doctors and 72-83% reporting weight stigma and discrimination, especially within their own families and social circles. Interpretation: This study underscores the urgent need for education addressing misconceptions about obesity's causes and controllability among HCPs and GenPop. Despite recognition of obesity as a disease, biological factors are underrepresented, and weight stigma drives healthcare avoidance. These findings highlight the importance of culturally sensitive education to reduce weight stigma and improve understanding of the complexity of obesity, and the promotion of empathy by recognizing the lived experiences faced by people living with obesity, for both Mexican HCPs and GenPop. Funding: An investigator-led grant awarded to Obesidades SC (where VVV is president) was received from Novo Nordisk to cover the cost of QualtricsTM participant pooling. The study was conceived and the methods designed by VVV and SWF before the investigator-led funding application. The sponsor had no role in study design, data collection, data analysis, data interpretation, or manuscript writing. The fee for open access publication in The Lancet Regional Health - Americas was covered by the Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán (INCMNSZ).