Our food system has significant impacts on the environment and dominates several of the transgressed planetary boundaries. To mitigate the environmental impacts of food production and consumption, we need quantitative and reliable information on the environmental impacts of food at different stages. This allows producers to mitigate their impacts, supply chain actors (processors, retailers, caterers) to source products with low impacts, consumers to guide their purchases towards low-impact food and policy makers to define adequate framework conditions for the food system. Life-Cycle Assessment (LCA) has developed over the last three decades into a standard method for the assessment of environmental impacts of products and the preferred method for eco-labelling. LCA is characterised by a comprehensive assessment of environmental impacts, ranging from the use of resources (land, water, minerals, metals), climate change, biodiversity, ecotoxicity, eutropication, acidification to impacts on human health. It considers the whole life cycle of a product from cradle to grave including raw materials, agricultural production means, agricultural production, processing, transport, storage, packaging, retail, consumption and final disposal. The environmental impacts are related to a unit of the product. Application of LCA in the agri-food sector encounters particular challenges such as the strong dependence on natural resources and open biological systems that are difficult to control. Impacts are highly variable in time and space, driven by complex environmental processes, and the production units are numerous and relatively small. Despite the high variability of environmental impacts, some general observations can be made: seasonality matters for fruits and vegetables, notably those stemming from fossil-heated greenhouses. The advantages of regional or domestic production and the role of transports (food miles) are generelly overestimated by the public but remain important for fruits and vegetables and foods transported via air freight. Packaging is important for some products only, notably beverages. To mitigate environmental impacts, the consumption of animal-sourced food, notably red meat should be reduced and food waste avoided as far and possible. Substitutes for meat revealed to be promising alternatives, while the generally lower nutritional values and higher water scarcity of milk substitutes speak less for them. To better reflect the trade-off between nutrition and environmental impacts, nutritional LCA, which combines LCA with the consideration of the nutritional profiles or human health impacts, has emerged. The methods are promising, but currently not standardised enough to be regularly included in eco-labelling.