Dietary change important for climate mitigation

Pharmacists often provide information about healthy eating and healthy lifestyle as part of their professional role. But should the information they provide change in the context of climate change? Food and diet have a considerable environmental impact and globally agriculture accounts for 30 per cent of greenhouse gas emissions (GHGs). If more people were to follow the current healthy eating guidance, ie the Eatwell plate guidelines published by the UK government, the resulting diet would have a reduced environmental impact. Given that meat is a focus of dietary environmental impact, much research is also looking at the possibility of climate mitigation through changing management of farm livestock, including the possibility to reduce emissions of methane and nitrous oxide from the livestock system.

However, a new paper, published in Nature Climate Change, focuses on food demand-side climate change mitigation options. It suggests that if current dietary trends continue, food production alone will reach (if not exceed) the global targets for total greenhouse gas emissions in 2050. Diet preferences are shifting globally toward higher meat western diets with a high GHG-impact and this, combined with a growing global population, imply that even if we manage to increase agricultural yields this will not be enough to meet projected food demands. Shifting to healthier diets across the world and reducing food waste are therefore important parts of a combination of solutions needed to ensure food security and avoid dangerous climate change the researchers argue.  

The researchers estimate that GHGs from food production will increase by 80 per cent if meat and dairy consumption continues to rise at its current rate. To mitigate this, the authors urge people to limit their meat consumption to two 85g portions of red meat and five eggs per week, as well as a portion of poultry a day. The paper does not quantify milk and dairy foods.

A significant environmental issue discussed in this research is that the average efficiency of livestock converting plant feed to meat is less than 3 per cent, and as we eat more meat, more arable cultivation is turned over to producing feedstock for animals that provide meat for humans. The losses at each stage are large, and as humans globally eat more and more meat, conversion from plants to food becomes less and less efficient, driving agricultural expansion and releasing more GHGs.  Although developing agricultural technology may well reduce the environmental impact of livestock, it is important that human beings also consider their consumption. Following the guidance of the Eatwell plate would be a useful start as the current government guidelines are potentially associated with a lower environmental impact than the diet that is currently being consumed across the UK population. Meat and eggs are a good source of protein as well as vitamins and minerals and balancing the diet as recommended by the Eatwell plate would be beneficial for public health and the environment.


Last updated
The Pharmaceutical Journal, Dietary change important for climate mitigation;Online:DOI:10.1211/PJ.2014.20066543

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