Environmental impacts and monetary costs of healthy diets worldwide

Abstract

Using real-world food price and greenhouse gas (GHG) emissions data for locally available food items in 171 countries, we measure how healthy diets could be obtained with the lowest possible emissions, compared to costs and emissions of the least expensive options and foods most commonly consumed. We find that foods with the lowest GHG emissions for a healthy diet would emit 0.67 kg CO2e. A healthy diet using the least expensive items in each country would emit 1.65 kg CO2e and cost 9.96. Ninety-one percent of the difference in emissions between the lowest-cost and lowest-emissions diets is driven by animal-source foods and starchy staples. Other food groups, especially fruits and vegetables, vary widely in cost but not in emissions. Results show how changes in food policy and choice can most cost-effectively support healthier and more sustainable diets worldwide.