Modelled health impacts of three stakeholder-selected policies to support healthy and environmentally sustainable population diets

Food production and consumption impacts both planetary and population health. This research aimed to estimate the impacts of three stakeholder-selected food policies for the New Zealand (NZ) population. These were modelled using a proportional multistate lifetable model through to health gains, health equity impacts, and health system costs/cost savings. Exempting core, sustainable foods from Goods and Services Tax resulted in 87,340 health adjusted life years (HALYs) (95% Uncertainty Interval (UI): 72,590 to 104,140) and health system cost savings of $925.0 Million (M), UI: $661.5 to $1220.3M. Education about healthy sustainable foods generated small health impacts (1,170 HALYs, UI: 930 to 1,430) and health system cost savings ($9.6M, UI: $6.8 to $12.9M). Māra kai (gardening for food) and community gardens generated 8,040 HALYs (UI: 4,720 to 11,800) and would cost the government $364.3M (UI: $267.6 to $464.6M). All scenarios produced more age-standardised per capita health gain for Māori (Indigenous population) than non-Māori. The first two policies were cost saving while the māra kai and community gardens policy was borderline cost-effective. These results show that these policies have the potential to improve population health and reduce NZ ethnic health inequities. Due to the up-front investment needed for these policies and the lag in generating health system costs savings, research into the policies wider benefits need to be considered alongside these results. Results could be used to inform diet policy in high-income countries. For NZ, careful policy design involving relevant stakeholders, including Māori communities, is needed to ensure health benefits are realised.