Book excerpt: Global food systems have radically changed over the last 50 years. Food production has more than doubled, diets have become more varied (and often more energy-intense) satisfying people’s preferences in terms of form, taste and quality, and numerous local, national and multi-national food-related enterprises have emerged providing livelihoods for millions. Nonetheless, over 800 million people are still hungry (70% of whom live in rural areas in developing countries), about two billion suffer from poor nutrition, and over two billion are overweight or obese. The resource use implications and environmental impacts of these food systems are significant. In general, of all economic activities, the food sector has by far the largest impact on natural resource use as well as on the environment. An estimated 60% of global terrestrial biodiversity loss is related to food production; food systems account for around 24% of the global greenhouse gas emissions and an estimated 33% of soils are moderately to highly degraded due to erosion, nutrient depletion, acidification, salinization, compaction and chemical pollution. The Food Systems working group of the International Resource Panel has prepared a comprehensive scientific assessment of the current status and dynamics of natural resource use in food systems and their environmental impacts. The IRP identifies opportunities for Resource Smart Food Systems responding to policy-relevant questions like what do sustainable food systems look like from a natural resource perspective? How can resource efficiency improvements be made to enhance food security? How to steer transition towards sustainable food systems? The report looks at food as a crucial connection point (a ‘node’) where various societal issues coincide, such as human dependence on natural resources, the environment, health and wellbeing. Rather than looking separately at resources such as land, water and minerals, the IRP has chosen a systems approach. The report looks at all the resources needed for the primary production of food, as well as for other food system activities (e.g. processing, distribution) considering not only the set of activities, but also the range of actors engaged in them and the outcomes in terms of food security, livelihoods and human health.