Fast food has become a dominant force in Canada’s dietary landscape due to urbanization, socio economic disparities, and cultural normalization, leading to serious public health and equity questions. This study seeks to understand the structural and behavioural influences of fast-food consumption and its implications for health vulnerability while exploring nutritional equity awareness and policy directions to reduce reliance on, and make better access to, healthier food alternatives. The study utilized a mixed-methods methodology combining primary data collected from a stratified random sample of 700 Canadians (aged 18–65) in urban, suburban, and rural settings utilizing a validated 21 item Likert-scale questionnaire, administered through Qualtrics, along with pilot testing and content validation, then descriptive and SEM analyses were performed in SPSS and AMOS. Mediation analysis and integration of secondary data from national health databases allowed economic risk modelling (via CAGR) to contextualize health vulnerabilities and predicted costs of fast-food-related health outcomes over 10 years. The results suggest that fast food consumption in Canada is shaped primarily by structural influences like accessibility, cost justification, cultural normalization, and advertising. Coupled with attitudinal influences, these structural and behavioral influences lead to increased perceived health vulnerability, particularly for those who are low-income, Indigenous, urban, and youth. Mediation analysis revealed that Nutritional Equity Awareness partially mediated these relationships. In addition, secondary data suggests a clear dose-response relationship between fast food frequency and increasing rates of obesity, mental health issues, and chronic illness, likely to cost Canada CAD 15.78 billion per year by 2034 if not addressed. Our study highlights the need for policy interventions that are integrated and equity-driven.