Habit and contextual influences on adolescent Fast-Food consumption with implications for sustainable diets

Unhealthy diets, overweight, and obesity have become significant public health challenges, particularly among adolescents whose dietary patterns are shifting away from traditional Mediterranean diets toward increased fast-food consumption (FFC). Industrialisation, urbanisation, and globalisation have transformed food environments, making ultra-processed, energy-dense foods such as fast food more accessible and affordable than fresh, nutritious alternatives. A total of 296 adolescents aged 12–18 years participated in the study. Data were analysed using Partial Least Squares Structural Equation Modelling, integrating habitual automaticity, environmental cues, and contextual triggers alongside traditional TPB constructs. The results show that higher maternal education reduces the use of fast food as a meal replacement; however, it does not significantly impact overall consumption frequency, indicating that external social and environmental factors may outweigh parental influence. Moreover, FFC persists regardless of adolescents’ exposure to advertising or promotions, underscoring the habit-driven nature of this behaviour. These findings emphasise the need for habit-focused interventions rather than relying solely on traditional awareness campaigns to curb adolescent fast-food consumption. Given the influence of behavioural automaticity and contextual triggers, policymakers should prioritise systemic interventions that reshape food environments, ensuring that healthier, sustainable options become the default choice in schools, public spaces, and urban settings.