Environmental impacts associated with UPF consumption: which food chain stages matter the most? <i>Findings from a representative sample of French adults</i>

Abstract Background Scientific literature about environmental pressures associated with dietary patterns has been considerably growing over the last decade. However, few studies have analyzed the environmental impacts associated with the consumption of ultra-processed food (UPF) and which steps of the food system that contribute most to environmental pressures. The objective of this study was to investigate, in a representative sample of the adult French population, the environmental pressures of diets according to UPF consumption. Methods The study was conducted in 2,121 adults of the French nationally representative survey INCA 3. Food intakes were analyzed to define the %UPF (in weight) in the diet according to NOVA classification. Using detailed environmental data of foods of Agribalyse, we could assess the contribution of UPF to 14 indicators of environmental pressure and details those related to the stage of the food consumed: production, processing, storage, packaging, transport and retailing at the food level. The data was described according to quintiles of % of UPF in the diet and analyzed using crude and energy-adjusted models. Results Compared to low consumers of UPF (Q1, median UPF= 7%), high consumers (Q5, median UPF= 35%) had a higher energy intake (+22%) which came along with different environmental pressures (e.g. +15% greenhouse gas emissions (GHGe), +17% land use, -7% water use and +8% cumulative energy demand). Higher pressures could be ascribed to higher energy. However, the processing and packaging stages were significant contributor to energy demand. In Q5, contributions of the UPF category to total pressure were 35%, 39%, 28% and 42% for GHGe, water use land use, and energy demand, respectively, while ranging from 11 to 15% in Q1. Conclusions Diets rich in UPF, compared to low, were overall associated with intensification in GHGe, land use, and energy demand and with higher contribution of post-farm stages, in particular processing regarding energy demand. Highlights Overall, higher UPF consumption was associated with higher environmental impact, in particular GHGE and land use Low UPF consumers had overall higher water footprint (due to their high fruit and vegetable intake) A large part of the higher pressures observed among participants with higher UPF consumption was explained by their higher dietary energy intake since the associations did not remain or were even reversed after energy adjustment Regardless of the % UPF in the diet, GHGe, land use and water use pressures mostly occurred at the stage of agricultural production, in contrast, packaging and processing stages were also important contributors to energy demand Contribution of the UPF category to total impact/pressure varied across indicators, with a high contribution of the UPF category to energy demand, due to the packaging and processing stages, but a low contribution to GHGe and land use, because higher consumers of UPF are lower consumers of animal products