Evidence
Every important statement on this site is a claim with a record: what it says, how strong the evidence is and why, what its limits are, and which sources support or challenge it.
Explore food footprints, nutrition and sources
Felt-unit conversion factors · Calculator assumptions and factors
How we rate evidenceThe site is being built ahead of its research database, and it says so on every number. A record is sample until someone has opened the original source and confirmed the figure, unit, geography and year; draft once that is done and a second read is outstanding; reviewed when it is signed off. These are the records we offer for citation. The comparison tool, the calculator and the country notes run on figures that state their source and their basis instead of a review status; they are documented on the food pages and in the calculator assumptions. What each state means.
| Records | Total | Reviewed | Draft | Sample |
|---|---|---|---|---|
| Sources | 36 | 10 | 0 | 26 |
| Claims | 13 | 6 | 0 | 7 |
| Statistics | 61 | 34 | 0 | 27 |
| Questions | 8 | 0 | 0 | 8 |
| Articles | 6 | 0 | 0 | 6 |
Yes. Animal foods produce most of food's emissions, and beef and lamb produce the most per gram of protein. Eating less of them lowers a diet's footprint substantially.
Beef is in a different league from plant proteins on emissions. Chicken and eggs sit in between.
Most farmland feeds animals, not people directly. That land delivers a relatively small share of our food.
Soy grown for tofu and soy milk is a small slice of the total. Most soy feeds chickens, pigs and cows.
Better, in some ways, but not low-impact. Soil carbon gains are real, limited, and temporary.
About ten land animals per person per year, most of them chickens. Fish are not counted individually, but likely add far more.
The animals we farm can feel pain. For fish the evidence is strong; for crabs and lobsters it is now considered substantial.
People eating plant-based diets have fewer heart attacks on average. Trials show these diets lower cholesterol, which supports a causal link.
It can be, if it is built on whole foods and covers a few nutrients. 'Vegan' on its own is not a health claim.
Yes. This is the one nutrient a vegan diet cannot supply on its own. A cheap supplement solves it.
Yes for most people. Beans, lentils, tofu, grains and nuts add up. Athletes and older adults should plan a little more deliberately.
Yes, in canteen settings. Doubling vegetarian availability raised vegetarian sales by roughly 8 to 15 percentage points, and almost nobody noticed the change.
Yes. Identically prepared vegetables were chosen 41% more often under a flavour label than a health-restrictive one, and 'meat-free' performed worse than almost every alternative tested.
Each record summarises what a source found, its limitations, funding, and which claims it supports or complicates, with a link to the original. Why we do this.
Joseph Poore, Thomas Nemecek (2018). Science.
Xiaoming Xu, Prateek Sharma, Shijie Shu et al. (2021). Nature Food.
Food and Agriculture Organization of the United Nations (2024). FAOSTAT database.
Jonathan Birch, Charlotte Burn, Alexandra Schnell et al. (2021). Report commissioned by the UK Government (Defra).
Lynne Sneddon, Robert Elwood, Shelley Adamo et al. (2014). Animal Behaviour.
Monica Dinu, Rosanna Abbate, Gian Franco Gensini et al. (2017). Critical Reviews in Food Science and Nutrition.
Fenglei Wang, Jusheng Zheng, Bo Yang et al. (2015). Journal of the American Heart Association.
Roman Pawlak, Scott Parrott, Sudha Raj et al. (2013). Nutrition Reviews.
François Mariotti, Christopher Gardner (2019). Nutrients.
Daniela Cusack, et al. (2021). Global Change Biology.
Tara Garnett, Cécile Godde, et al. (2017). Food Climate Research Network, University of Oxford.
Samantha Kuzma, Marc F. P. Bierkens, Shivani Lakshman et al. (2023). WRI Technical Note.
Various national LCA studies (2024). Compiled by The Balance of Health.
FAO Food Balance Sheets, UK National Diet and Nutrition Survey, USDA Economic Research Service et al. (2024). Compiled by The Balance of Health.
UK Eatwell Guide, German Nutrition Society (DGE), Nordic Nutrition Recommendations et al. (2024). Compiled by The Balance of Health.
World Animal Protection Animal Protection Index, EU Directive 98/58/EC and species directives, UK Animal Welfare Act 2006 et al. (2024). Compiled by The Balance of Health.
US Department of Agriculture, Agricultural Research Service (2024). USDA.
A. M. J. Gilsing et al. (2010). .
Monica Crippa et al. (2021). .
Peter Scarborough et al. (2023). .
WRAP (2021). .
Franz Weiss and Adrian Leip (2012). .
C. Alan Rotz et al. (2019). .
Christel Cederberg et al. (2011). .
Alison Mood, Elena Lara, Natasha Boyland and Phil Brooke (2023). .
Alison Mood and Phil Brooke, Fishcount (2020). .
Academy of Nutrition and Dietetics (2025). .
ESPGHAN Nutrition Committee (2025). .
Institute of Medicine (2005). .
Food and Agriculture Organization of the United Nations (2026). .
Food Standards Australia New Zealand (2009). .
Australian Government Department of Agriculture (2023). .
Australian Parliament (2024). .
Brazil Ministry of Health (2014). .
ANVISA (2017). .
Chinese Nutrition Society (2022). .
World Health Organization (2014). .
World Animal Protection (2020). .
German Nutrition Society (2024). .
Nordic Council of Ministers (2023). .
UK Government (2024). .
Council of the European Union (1998). .
Council of the European Union (1999). .
Council of the European Union (2008). .
Law Commission of India (2017). .
Japan Ministry of the Environment (1973). .
USDA and HHS (2020). .
US Food and Drug Administration (1996). .
British Dietetic Association (2025). .
Press Information Bureau, Government of India (2024). .
Theodore T. Zava and David T. Zava (2011). .
(2024). International Tennis Federation.
(2024). International Football Association Board.
(2024). Department for Energy Security and Net Zero.
(2013). Energy Saving Trust.
(2024). Department for Environment, Food and Rural Affairs.
Emma S. Garnett, Andrew Balmford, Chris Sandbrook et al. (2019). Proceedings of the National Academy of Sciences.
(2023). French university catering research group.
(2020). World Resources Institute, Better Buying Lab.
Bradley P. Turnwald, Alia J. Crum (2019). Psychological Science.
(2022). University research group.
Gregg Sparkman, Gregory M. Walton (2017). Psychological Science.