Access to sufficient and clean freshwater is essential for all life. Water is also essential for the functioning of food systems: as a key input into food production, but also in processing and preparation, and as a food itself. Water scarcity and pollution are growing, affecting poorer populations most, and particularly food producers. Malnutrition levels are also on the rise, and this is closely linked to water scarcity. The achievement of Sustainable Development Goals (SDG) 2 and 6 are co-dependent. Solutions for jointly improving food systems and water security outcomes include: (1) strengthening efforts to retain water-based ecosystems and their functions; (2) improving agricultural water management for better diets for all; (3) reducing water and food losses beyond the farmgate; (4) coordinating water with nutrition and health interventions; (5) increasing the environmental sustainability of food systems; (6) explicitly addressing social inequities in water-nutrition linkages; and (7) improving data quality and monitoring for water-food system linkages, drawing on innovations in information and communications technology (ICT). Climate change and other environmental and societal changes make the implementation and scaling of solutions more urgent than ever.

The role of water quality, particularly its impact on health, environment and wider well-being, are rarely acknowledged in the water–energy–food (WEF) nexus. Here we demonstrate the necessity to include water quality within the water dimension of the WEF nexus to address complex and multi-disciplinary challenges facing humanity. Firstly, we demonstrate the impact of water quality on the energy and food dimensions of the WEF nexus and vice versa at multiple scales, from households to cities, regions and transboundary basins. Secondly, we use examples to demonstrate how including water quality would have augmented and improved the WEF analysis and its application. Finally, we encourage hydrological scientists to promote relevant water quality research as addressing WEF nexus challenges. To make tangible progress, we propose that analysis of water quality interactions focuses initially on WEF nexus “hotspots,” such as cities, semi-arid areas, and areas dependent on groundwater or climate change-threatened meltwater.

Copyright © The Author(s) 2020.Background: Ultra-processed foods (UPF) have been associated with major diet-related public health issues that share underlying drivers with climate change. Both challenges require major changes to the food system and so the potential benefits to health and the environment present a double motivation for transformation. Our aim is to assess the impacts of UPF on total greenhouse gas emissions (GHGE), water and ecological footprints in Brazil food purchases. Methods: We have used data from 4 Brazilian Household Budget Surveys (1987, 1996, 2003, 2009). Each food item was classified into NOVA food groups (unprocessed/minimally processed, culinary ingredients, processed and ultra-processed). The information was linked to nutrition and footprint data. Purchases were converted into grams per capita per day to estimate total energy (kcal), percentage of energy from UPF, as well as total GHGE, water and ecological footprints. We performed linear regression to calculate year-adjusted means of footprints per 1000 Kcal by year-specific quintiles of UPF participation in the total energy. The data were analysed in R v.3.6.1 and STATA SE 14.1. Results: The mean UPF participation in total energy varied from 13% (SD 2.4) in the 1st UPF quintile to 29% (SD 5.1) in the 5th quintile. The footprints increased linearly across quintiles: the mean g CO2eq varied from 1312 in the 1st to 1721 in the 5th UPF quintile (p-trend<0.001); the mean litres of water varied from 1420 in the 1st to 1830 in the 5th quintile (p-trend<0.001); the mean m2 varied from 9.4 in the 1st to 12.3 in the 5th quintile (p < 0.001). Conclusions: The environmental impacts were higher for Brazilian diets with a larger fraction of energy from UPF. Specifically, low UPF diets seem to have lower GHGE, water and ecological footprints. Our findings offer new motivators for dietary change to simultaneously healthier and more sustainable eating patterns and will be of relevance to consumers and policymakers. Key messages: * Diets high in UPF cause more climate impact than diets with lower levels of UPF. * Healthy and sustainable dietary patterns should be low in ultra-processed foods.