Objective:While associations of ultra-processed food (UPF) consumption with adverse health outcomes are accruing, its environmental and food biodiversity impacts remain underexplored. This study examines associations between UPF consumption and dietary greenhouse gas emissions (GHGe), land use and food biodiversity.

Design:Prospective cohort study. Linear mixed models estimated associations between UPF intake (g/d and kcal/d) and GHGe (kg CO2-equivalents/day), land use (m2/d) and dietary species richness (DSR). Substitution analyses assessed the impact of replacing UPF with unprocessed or minimally processed foods.

Participants:368 733 participants in the European Prospective Investigation into Cancer and Nutrition (EPIC) study.

Setting:Europe.

Results:Stronger associations were found for UPF consumption in relation with GHGe and land use compared with unprocessed or minimally processed food consumption. Substituting UPF with unprocessed or minimally processed foods was associated with lower GHGe (8·9 %; 95 % CI: –9·0, –8·9) and land use (9·3 %; –9·5; –9·2) when considering consumption by gram per day and higher GHGe (2·6 %; 95 % CI: 2·5, 2·6) and land use (1·2 %; 1·0; 1·3) when considering consumption in kilocalories per day. Substituting UPF by unprocessed or minimally processed foods led to negligible differences in DSR, both for consumption in grams (–0·1 %; –0·2; –0·1) and kilocalories (1·0 %; 1·0; 1·1).

Conclusion:UPF consumption was strongly associated with GHGe and land use as compared with unprocessed or minimally processed food consumption, while associations with food biodiversity were marginal. Substituting UPF with unprocessed or minimally processed foods resulted in differing directions of associations with environmental impacts, depending on whether substitutions were weight or energy based.