What environmental impact can an individual have by adopting a vegetarian or vegan diet?
Oxford University’s LEAP project (Scarborough et al., 2023) analysed dietary data from more than 55,000 people and linked it with environmental data from over 38,000 farms across 119 countries. Compared with high meat consumers (defined as those eating more than 100g of meat per day), individuals following a vegan diet generated substantially lower environmental impacts, including:
75% lower greenhouse gas emissions
75% lower land use
54% lower water use
73% lower eutrophication (water pollution)
66% lower biodiversity loss
Additional evidence comes from a study conducted by the University of Granada and the Spanish National Research Council (Alcalá-Santiago et al., 2025), which compared an omnivorous Mediterranean-style diet with moderate meat consumption against pesco-vegetarian, ovo-lacto-vegetarian, and vegan dietary patterns. The study found that daily greenhouse gas emissions fell progressively as animal product consumption decreased:
Omnivorous diet: 3.8 kg CO₂e per day
Pesco-vegetarian diet: 3.2 kg CO₂e per day
Ovo-lacto-vegetarian diet: 2.6 kg CO₂e per day
Vegan diet: 2.1 kg CO₂e per day
These findings demonstrate that dietary shifts towards plant-based eating can significantly reduce an individual's environmental footprint while also supporting public health objectives.
Same in Hong Kong, health authorities also encourage eating less meat to benefit personal health and tackle climate change.3
Further readings
1. Scarborough, P., Clark, M., Cobiac, L. et al. Vegans, vegetarians, fish-eaters and meat-eaters in the UK show discrepant environmental impacts. Nat Food 4, 565–574 (2023).
2. Alcalá-Santiago Á, Rodríguez-Martín NM, Casas-Albertos E, Gálvez-Navas JM, Castelló-Pastor A, García-Villanova B and Molina-Montes E (2025) Nutrient adequacy and environmental foot-print of Mediterranean, pesco-, ovo-lacto-, and vegan menus: a modelling study. Front. Nutr. Volumn 12 (2025)
3. A ‘Meaty’ Matter. Non-Communicable Disease Watch. 2017. Centre for Health Protection, Department of Health. Hong Kong.
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