Our Methodology

When a restaurant serves a plant-based meal instead of an animal-based one, something real happens to the planet. We measure that something — and we're transparent about how we do it.

Every meal tracked through Eat for Impact is assigned an estimated greenhouse gas savings, water savings, and land savings based on what was replaced and what replaced it.

Our Primary Source

Our emissions estimates are grounded in the Poore & Nemecek (2018) study, one of the most comprehensive analyses of food's environmental impact ever published. It examined data from over 38,000 farms across 119 countries and covered the full supply chain — from land use to processing to transportation to retail.

You can explore the study and its data at Our World in Data: ourworldindata.org/environmental-impacts-of-food

What We Measure

For each meal transition, we calculate the difference between the environmental footprint of the animal-based item and its plant-based equivalent across three categories:

• Greenhouse Gas Emissions — measured in kilograms of CO₂ equivalent (kg CO₂e). This accounts for carbon dioxide, methane, and nitrous oxide across the full production chain.
• Water Use — measured in liters per serving. This reflects the total freshwater consumed or polluted in producing the food, not just what's used in cooking.
• Land Use — measured in square meters per serving. Animal agriculture requires significantly more land, both for grazing and for growing feed crops.

The Numbers We Use

We use mean and high-end figures from the Poore & Nemecek (2018) dataset, which better reflect real-world conditions of commercial food production at scale — including feed inefficiencies, transportation, and processing losses — rather than optimized low-emission outliers. We disclose this so our numbers can be evaluated honestly.

Per-serving emissions figures we apply to common animal proteins: Beef 14.9 kg CO₂e · Lamb 6.0 · Chicken 4.5 · Fish (farmed) 3.0 · Pork 2.25 · Eggs 0.7 · Cow's milk 1.5 · Cheese 3.0. Our blended average for a plant-based serving is approximately 0.83 kg CO₂e. Our average estimated savings per switched meal: 10.3 kg CO₂e.

Supplementary Sources

• Plant milks — Our World in Data: ourworldindata.org/environmental-impact-milks
• Plant-based cheese — Violife Life Cycle Assessment Technical Summary (2021): violifefoods.com (PDF)
• Plant-based eggs (JUST Egg) — Ethical Bargains Sustainability Review: ethicalbargains.org
• Water footprint data — Water Footprint Network via Water Calculator: watercalculator.org