The anthropogenic nitrogen turnover of Western societies is highly unbalanced. As a consequence, a permanent supply of nitrogen via mineral fertiliser (produced with high energy inputs) and/or imported fodder are required and result in significant impacts of nitrogen emissions on the environment (air, water, soil). Key factors to an improved nitrogen balance on a national scale are the nutrition habits of the population. According to primary calculations a shift from the actual animal-based nutrition to a "healthier nutrition" (mainly characterised by 2/3 vegetable protein supply) would lead to a reduction of needed nitrogen supply as well as of nitrogen emissions to the environment by about one quarter to one third on a national scale. More detailed investigations are required in this respect in order to arrive at more specific conclusions and have commenced by an interdisciplinary team led by the authors.