Sources & research

Poore and Nemecek assembled environmental data across many producers and food products. Life-cycle assessment examines impacts across stages of production and distribution under defined boundaries. It can reveal differences between foods and variation between producers. The study is central to understanding why dietary choices matter across several environmental dimensions.

An average does not describe every farm or meal. Allocation methods, land-use assumptions and units of comparison influence results. Read whether a figure is expressed per kilogram, calorie or amount of protein. Use life-cycle evidence to understand patterns, and avoid treating a single quoted number as universal or timeless.

The UK study by Scarborough and colleagues connects reported diets with environmental impact data. It supports comparing dietary patterns across emissions, land and other dimensions. Whole-diet studies are valuable because people eat combinations of foods, but they involve assumptions about dietary reporting and the supply chains represented in the underlying data.

The relative charts on this site simplify the study’s findings for readability. They are not a substitute for the paper’s methods and uncertainty intervals. Do not transfer a UK-specific percentage mechanically to a different national food system or an individual household. Context matters even when the overall direction is consistent.

Wynes and Nicholas examine the mitigation potential of personal actions and the gap between impactful options and public advice. The work helps put diet, travel and energy changes in context. Its estimates describe particular scenarios and evidence available at publication, rather than a continuously updated ranking for every location.

Our action chart uses illustrative annual values from literature-based comparisons. Its categories are useful for orientation, but real outcomes depend on baseline behaviour and local conditions. Treat the comparison as a discussion aid. A current personal decision may require more specific information about your vehicle, electricity supply or flight route.

IPCC and IPBES assessments synthesize large bodies of research about climate, land and biodiversity. They provide broad context for food-system change and the role of institutions. Our World in Data offers accessible charts and explanations, often linking back to underlying studies. These are different forms of evidence with different purposes.

A synthesis report is not necessarily the source of a precise recipe-level number. An explainer is useful for understanding but should not replace the original study when methods matter. Follow the chain from a headline to its source, and ask whether the evidence actually addresses the claim being made.

Environmental life-cycle studies do not establish dietary adequacy for every life stage. Nutrition guidance addresses a different question and should come from qualified health sources. Similarly, household waste strategies and global food-waste estimates use different methods from diet-emission comparisons. Combining these topics is useful only when their boundaries remain clear.

The NHS vegan-diet guidance and UNEP Food Waste Index provide complementary starting points. Read local food-safety advice for storage and individualized professional guidance for health needs. Avoid asking one study to answer every sustainability question. A strong platform uses several kinds of evidence and explains why each is relevant.