This study focuses on UK diets. It finds that if in average diets conformed to WHO recommendations, associated GHG emissions would be reduced by 17%. Further reductions of up to 40% can be achieve through dietary shifts that include a reduction in animal products and processed snacks, and more fruit and vegetables.
Abstract and conclusions as follows:
The UK has committed to reduce greenhouse gas (GHG) emissions by 80 % relative to 1990 levels by 2050, and it has been suggested that this should include a 70% reduction in emissions from food. Meeting this target is likely to require significant changes to diets, but the likely effect of these changes on population nutritional intakes is currently unknown. However, the current average UK diets for men and women do not conform to WHO dietary recommendations, and this presents an opportunity to improve the nutritional content of diets while also reducing the associated GHG emissions. The results of this study show that if, in the first instance, average diets among UK adults conformed to WHO recommendations, their associated GHG emissions would be reduced by 17 %. Further GHG emission reductions of around 40 % could be achieved by making realistic modifications to diets so that they contain fewer animal products and processed snacks and more fruit, vegetables and cereals. However, our models show that reducing emissions beyond 40 % through dietary changes alone will be unlikely without radically changing current consumption patterns and potentially reducing the nutritional quality of diets.
This study has shown that considerable reductions in the GHG emissions associated with diets can be achieved while still maximising the nutritional content and acceptability of the diet. However, the dietary changes required to achieve these co-benefits may be more complex than many studies assume. Our dietary optimisations show that emissions reductions can be achieved by reducing consumption of animal products, switching to meats and dairy products with lower associated emissions (e.g., pork, chicken and milk), reducing consumption of savoury snacks, switching to fruits and vegetables with lower emissions, and increasing consumption of cereals. The optimised diet stops short of suggesting that the universal adoption of vegetarianism or veganism is essential (which will not be currently acceptable to large sections of the population). However there are limits to the extent of cuts in emissions that can be achieved and our findings indicate that additional strategies such as reducing food waste and increased efficiency will be essential if the food and agricultural sector is to play its full part in contributing to national GHG reduction targets, especially as increased cereal crops will also be required in order to meet the global demand for animal products in future (Pradhan et al. 2013) This information will be of use to public health, food and environment policy makers, as they suggest that benefits to both health and the environment could be considerable if such policies can be successfully implemented.
Green, R., Milner, J., Dangour, A.D., Haines, A., Chalabi, Z., Markandya, A., Spadaro, J., Wilkinson, P. (2015) The potential to reduce greenhouse gas emissions in the UK through healthy and realistic dietary change, Climatic Change
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