Healthy and sustainable diets that meet greenhouse gas emission reduction targets and are affordable for different income groups in the UK

Objective: To model dietary changes required to shift the UK population to diets that meet dietary recommendations for health, have lower greenhouse gas emissions (GHGE) and are affordable for different income groups.

Design: Linear programming was used to create diets that meet dietary requirements for health and reduced GHGE (57% and 80% targets) by income quintile, taking into account food budgets and foods currently purchased, thereby keeping dietary change to a minimum.

Subjects: Nutrient composition, GHGE and price data were mapped to 101 food groups in household food purchase data (UK Living Cost and Food Survey (2013), n=5144 households).

Results: Current diets of all income quintiles had similar total GHGE, but the source of GHGE differed by types of meat, and amount of fruit and vegetables. It was possible to create diets with a 57% reduction in GHGE that met dietary and cost restraints in all income groups. In the optimised diets, the food sources of GHGE differed by income group due to the cost and keeping the level of deviation from current diets to a minimum. Broadly, the changes needed were similar across all groups; reducing animal-based products and increasing plant-based foods but varied by specific foods.

Conclusions: Healthy and lower GHGE diets could be created in all income quintiles but tailoring changes to income groups to minimise deviation may make dietary changes more achievable. Specific attention must be given to interventions and policies to be appropriate for all income groups.