Weight bias internalization and beliefs about the causes of obesity among the Canadian public

Background Explicit weight bias is known as negative attitudes and beliefs toward individuals due to their weight status and can be perpetuated through misconceptions about the causes of obesity. Individuals may also experience weight bias internalization (WBI) when they internalize negative weight-related attitudes and self-stigmatize. There is a paucity of research on the beliefs about the causes of obesity and the prevalence of WBI among public Canadian samples. The aim of this study was to describe these attitudes and beliefs about obesity among a large Canadian sample across the weight spectrum. Methods A Canadian sample of adults ( N = 942; 51% Women; mean age group = 45–54 years; mean body mass index [BMI] = 27.3 ± 6.7 kg/m 2 ) completed an online questionnaire. Participants completed the Modified Weight Bias Internalization Scale, the Anti-Fat Attitudes Questionnaire, and the Causes of Obesity Questionnaire. Results Mean WBI score within the entire sample was 3.38 ​​ ± 1.58, and females had higher mean scores as compared to males ( p < 0.001). Mean scores were also higher among individuals with a BMI of > 30 kg/m 2 (4.16 ± 1.52), as compared to individuals with a BMI of 25–30 kg/m 2 (3.40 ± 1.50), and those with a BMI of 20–25 kg/m 2 or below 18.5 kg/m 2 (2.81 ± 1.44) ( p < 0.001 for all). Forty four percent of Canadians believed behavioural causes are very or extremely important in causing obesity, 38% for environmental causes, 28% for physiological and 27% for psychosocial causes. Stronger beliefs in behavioural causes were associated with higher levels of explicit weight bias. No BMI differences were reported on the four different subscales of the Causes of Obesity Questionnaire. Conclusions Weight bias internalization is prevalent among Canadians across all body weight statuses, and the public endorses behavioural causes of obesity, namely physical inactivity and overeating, more than its other causes. Findings warrant the reinforcement of efforts aimed at mitigating weight bias by educating the public about the complexity of obesity and by highlighting weight bias as a systemic issue that affects all Canadians living in diverse body weight statuses.