The Impacts of Dietary Change on Greenhouse Gas Emissions, Land Use, Water Use, and Health: A Systematic Review

Abstract

Food production is a major driver of greenhouse gas (GHG) emissions, water and land use, and dietary risk factors are contributors to non-communicable diseases. Shifts in dietary patterns can therefore potentially provide benefits for both the environment and health. However, there is uncertainty about the magnitude of these impacts, and the dietary changes necessary to achieve them. We systematically review the evidence on changes in GHG emissions, land use, and water use, from shifting current dietary intakes to environmentally sustainable dietary patterns. We find 14 common sustainable dietary patterns across reviewed studies, with reductions as high as 70–80% of GHG emissions and land use, and 50% of water use (with medians of about 20–30% for these indicators across all studies) possible by adopting sustainable dietary patterns. Reductions in environmental footprints were generally proportional to the magnitude of animal-based food restriction. Dietary shifts also yielded modest benefits in all-cause mortality risk. Our review reveals that environmental and health benefits are possible by shifting current Western diets to a variety of more sustainable dietary patterns.

Identification of data-driven Dutch dietary patterns that benefit the environment and are healthy

“…Our results for environmental impact of the dietary patterns may therefore not be directly extrapolated to other countries where production methods, productivity, fossil energy use, in-and export, and ways of transport may differ. However, the average GHG emissions of the diet seem comparable to previous studies (Aleksandrowicz et al 2016;Nelson et al 2016). …”

“…On average, for every 10 points higher score on the DHD15-index (0 to 140 points), dietary GHG emissions were 0.2 kg CO 2 -equivalents per day lower. This analysis included an a priori determined healthy dietary pattern and the finding confirms recent review study results (Aleksandrowicz et al 2016;Nelson et al 2016).…”

“…This WHO-UK diet would result in a 17% reduction in GHG emissions. Applying more drastic dietary changes such as leaving out meat or fish would result in much larger reductions in GHG emissions (20-30% (Aleksandrowicz et al 2016)) than from consuming our BPlant-based Pattern( 3%). This implies two things.…”

“…However, significant smaller changes are observed when these constraints are taken into account (Aleksandrowicz et al 2016). Green et al used an optimization tool to model the current UK diet so that it meets the WHO guidelines (Green et al 2015).…”

“…In addition, no direct association was observed between diet-related GHG emissions and mortality risk in a previous study (Biesbroek et al 2014). However, adhering to a vegetarian or Mediterranean-style dietary pattern has been shown to be associated with lower environmental impacts and better health (Aleksandrowicz et al 2016;Hallström et al 2015;Nelson et al 2016).…”