Study Reveals Widespread Misconceptions About Food’s Environmental Impact

Introduction

Environmental scientists have long known that dietary choices significantly influence greenhouse-gas emissions, biodiversity loss, and freshwater use. Yet policy efforts to shift consumption patterns have stumbled over a simple question: do consumers actually understand which foods are the most harmful? A new peer-reviewed study led by the University of Nottingham’s School of Psychology suggests the answer is a resounding “no.”

Using an interactive online task, researchers asked 168 UK adults to classify 40 common supermarket items—ranging from beef burgers to almonds—according to perceived environmental impact. When the participants’ personal rankings were compared with life-cycle assessment data, large and consistent gaps emerged. These misperceptions, the authors argue, undermine voluntary sustainability pledges and complicate eco-labeling initiatives slated for rollout across Europe.

Why Food Footprints Matter

Food systems account for roughly one-third of global anthropogenic greenhouse-gas emissions. Agriculture drives 80 percent of deforestation and is the single largest consumer of freshwater. While technological efficiencies can curb some impacts, modelling work by the EAT-Lancet Commission shows that dietary change is indispensable for meeting both climate targets and nutritional needs. Accurate consumer perception is therefore a prerequisite for market-based shifts toward lower-impact eating patterns.

Study Design and Methodology

Participants were recruited through the UK-representative Prolific platform. After completing a short demographic survey, they entered a drag-and-drop interface where they arranged 40 product cards into self-defined impact categories (e.g., “Low,” “Medium,” “High,” or more granular bins). Products spanned fresh produce, animal proteins, plant proteins, and ultra-processed convenience foods. Next, the software revealed the scientifically estimated cradle-to-grave impacts—shown as CO₂-equivalents per kilogram—and participants indicated whether each value was “higher,” “about what I expected,” or “lower” than anticipated. Finally, they stated their intention to increase, maintain, or decrease future purchases of each item.

The researchers then performed a principal-component analysis to uncover the mental models guiding perceptions. Two latent factors explained over 70 % of variance:

Animal vs. plant origin – People reflexively ranked animal products as worse.
Degree of processing – Highly processed foods were assumed to carry larger footprints, regardless of underlying ingredients.

Key Findings

1. Overestimation of Processed Plant Foods

Items such as meat-free ready meals and oat milk desserts were consistently placed in the highest impact tier, despite having moderate footprints relative to animal products. The “processing heuristic” appeared to override ingredient-based reasoning.

2. Underestimation of Water-Intensive Crops

Many participants ranked almonds, avocados, and olive oil as environmentally benign. In reality, tree nuts require large amounts of irrigation water and generate 2–6 kg CO₂-eq kg⁻¹—comparable to chicken meat.

3. Beef Blind Spot

Although beef was correctly identified as high-impact, the magnitude of its footprint (≈ 60 kg CO₂-eq kg⁻¹) surprised 84 % of respondents. Poultry, by comparison, averages 6 kg CO₂-eq kg⁻¹, a ten-fold difference that participants underestimated by roughly half.

4. Binary Plant–Animal Thinking

Within-category distinctions were weak. Respondents rarely differentiated between cheese (≈ 21 kg CO₂-eq kg⁻¹) and eggs (≈ 4 kg CO₂-eq kg⁻¹), grouping both simply as “animal.”

5. Intention to Change

Surprise predicted behavioural intention: items whose impacts were higher than expected (beef, nuts) elicited the strongest stated willingness to reduce consumption.

Implications for Policymakers and Industry

The results underscore the limitations of binary “plant good, animal bad” messaging. Without nuanced information, consumers may swap beef for cheese—achieving minimal climate benefit—or avoid processed plant-based burgers that actually deliver substantial emission reductions relative to meat equivalents. The authors recommend:

Multi-indicator eco-labels: A single A–E or traffic-light grade synthesising greenhouse-gas emissions, land use, and water scarcity into one score.
Targeted education: Public campaigns highlighting the exceptionally high footprint of beef and the relatively modest impact of poultry and eggs.
Reformulation incentives: Processed foods can be optimised for sustainability; governments should reward manufacturers that replace high-impact ingredients (e.g., dairy, palm oil) with lower-impact alternatives.

Consumer Takeaways

Don’t equate processing with high emissions; ingredient choice matters more.
Beef reduction offers the single most effective dietary lever for shrinking food-related carbon footprints.
Tree nuts, while nutritious, should be consumed in moderation from a planetary perspective.
Use lifecycle data apps such as MyClimate or Poore & Nemecek’s database to verify perceptions.

Future Directions

The Nottingham team is currently testing whether A–E eco-labels shift real-world purchases in a virtual supermarket experiment. Parallel work is exploring cultural transferability: preliminary data from Brazil and India suggest the animal/plant heuristic is pervasive, but the processing bias varies with national dietary patterns. Long-term, integration of environmental impact labels into existing nutrient-profiling algorithms could provide consumers with unified guidance on health and sustainability.

Conclusion

Accurate consumer knowledge is the linchpin of sustainable food transitions. The University of Nottingham study demonstrates that intuition alone is insufficient: without lifecycle data, even well-intentioned shoppers misallocate their attention, fretting over processed plant-based meals while underestimating the outsized impact of everyday luxuries like almonds and cheese. Transparent, easy-to-compare eco-labels—backed by robust life-cycle assessment—offer a pragmatic path to align dietary choices with climate ambitions.

References

Fletcher, D. et al. (2025). “Dimensions underlying public perceptions and misperceptions of food’s environmental impact.” Journal of Cleaner Production, 531, 146938. DOI: 10.1016/j.jclepro.2025.146938

Source press release: ScienceDaily