Dietary greenhouse gas emissions of meat-eaters, fish-eaters, vegetarians and vegans in the UK

TLDR

Animal-based foods produce higher greenhouse gas emissions than plant-based foods. The study aimed to quantify dietary GHG emissions differences among self‑selected meat‑eaters, fish‑eaters, vegetarians, and vegans in the UK. Using EPIC‑Oxford data, 2,041 vegans, 15,751 vegetarians, 8,123 fish‑eaters, and 29,589 meat‑eaters (aged 20–79) were assessed with a validated food frequency questionnaire, GHG values for 94 UK food commodities were applied, and ANOVA adjusted for sex and age estimated average 2,000‑kcal diet emissions. Adjusted mean emissions were 7.19, 5.63, 4.67, 3.91, 3.81, and 2.89 kgCO₂e day for high, medium, low meat‑eaters, fish‑eaters, vegetarians, and vegans respectively, showing meat‑eaters emit roughly twice as much as vegans, indicating that reducing meat consumption could lower dietary GHG emissions.

Abstract

The production of animal-based foods is associated with higher greenhouse gas (GHG) emissions than plant-based foods. The objective of this study was to estimate the difference in dietary GHG emissions between self-selected meat-eaters, fish-eaters, vegetarians and vegans in the UK. Subjects were participants in the EPIC-Oxford cohort study. The diets of 2,041 vegans, 15,751 vegetarians, 8,123 fish-eaters and 29,589 meat-eaters aged 20–79 were assessed using a validated food frequency questionnaire. Comparable GHG emissions parameters were developed for the underlying food codes using a dataset of GHG emissions for 94 food commodities in the UK, with a weighting for the global warming potential of each component gas. The average GHG emissions associated with a standard 2,000 kcal diet were estimated for all subjects. ANOVA was used to estimate average dietary GHG emissions by diet group adjusted for sex and age. The age-and-sex-adjusted mean (95 % confidence interval) GHG emissions in kilograms of carbon dioxide equivalents per day (kgCO2e/day) were 7.19 (7.16, 7.22) for high meat-eaters ( > = 100 g/d), 5.63 (5.61, 5.65) for medium meat-eaters (50-99 g/d), 4.67 (4.65, 4.70) for low meat-eaters ( < 50 g/d), 3.91 (3.88, 3.94) for fish-eaters, 3.81 (3.79, 3.83) for vegetarians and 2.89 (2.83, 2.94) for vegans. In conclusion, dietary GHG emissions in self-selected meat-eaters are approximately twice as high as those in vegans. It is likely that reductions in meat consumption would lead to reductions in dietary GHG emissions.