BACKGROUND: Evidence suggests we must change both the type of food we consume and the way we produce it, at a transformational scale, to protect population and planetary health and avoid exacerbating existing diet-related health inequalities. DISCUSSION: We summarise key findings from behaviour change theory and literature, highlighting the need for means, motive and opportunity to enact behaviour change. We evaluate and contrast the implications for interventions aimed at individuals vs. businesses, arguing that policy must shift focus from individual responsibility to systemic change. CONCLUSION: Past public health interventions have tended to focus on individuals' motivation, with limited impact, while interventions that target the motivation of businesses, if enacted, would likely garner substantially greater impact. Governments implementing mandatory reporting could provide the foundation to realign the incentives that shape business practices. This would subsequently enable mandatory targets to be introduced on foods sold, providing in turn the necessary conditions - the means and opportunity - for individuals to enact dietary change.