Behavioural Nudges for Sustainable Food Choices: A Critical Narrative Review of Effectiveness, Autonomy, and Responsible Food-System Governance

Behavioural nudges modify choice architecture to steer food choices without removing alternatives or substantially changing economic incentives. This critical narrative review synthesises 62 sources from behavioural public policy, public health nutrition, food ethics, and sustainable food-system governance. It distinguishes healthy food nudges, sustainable food nudges, green nudges, and responsible food-system interventions, and compares availability, placement, defaults, labels, digital architecture, and mixed policy packages. The evidence shows that nudges influence immediate food selection, but effects are heterogeneous and weaker for sustained environmental outcomes. Price instruments address affordability, nudges address attention and convenience, and boosts strengthen decision competence; none can substitute for the others. Ethical acceptability requires a transparent, calibrated opt-out process, equity monitoring, disclosure of commercial motives, democratic accountability, and integration with structural policy. Public institutions and profit-driven digital platforms therefore require different governance safeguards. Nudges are most defensible as components of coordinated food-system policy rather than stand-alone solutions.