Our daily food intake is also an important field of action. "You are what you eat" – when it comes to our daily diet, it is also about maintaining the health and well-being of each individual. More than any other field of action, this is where the personal, individual level meets the major overarching challenge of environmental pollution and resource consumption.

Therefore, the food system is a very complex product-service system in a changing society. In addition to traditional producers and the structures of the retail trade, the out-of-home catering (i.e. system catering, schools, company catering and even restaurants) is becoming increasingly the focus of research. In the context of sustainable development, this offers an important regulation element. Almost every German household dines out, instead of eating at home for every third to fourth meal (with a tendency to even more frequently). Strategies for a sustainable transition in the food industry require comprehensive analyses.

On the one hand, the production and manufacturing processes of individual links in the value chains must be examined, for example by calculating the material flows using the "Corporate Material Footprint" method within the "Sustainable McDonald's Deutschland" project. Or central ecological and social challenges must be identified using the hot-spot analysis method, as applied in the "REWE-Navi"project. On the other hand, individual consumption patterns are very crucial. For instance, the consumption of meat and meat products, as well as milk and dairy products – i.e. highly processed animal proteins – is and will remain a problem. But vegetarian or vegan diets can also pose environmental and health challenges.
The Wuppertal Institute sees itself as a driving force when it comes to defining target values for sustainable diets, which, in contrast to the health aspect, do not exist in a binding form for the environmental impact of a daily diet, yet.

Against the background of this discussion, the Nutritional Footprint was developed as an instrument to assess individual meals. It makes it possible to identify health and environmental impacts simultaneously. The method is constantly being further developed.