A criticism of the land-sparing approach to preserving biodiversity, by restricting farmland to a smaller, higher-yielding area, is that other impacts are higher in food produced this way. This study aims to investigate the evidence for this based on currently available data and models for greenhouse gas emissions, N, P and soil loss and water use. We asked 25 experts to identify and supply data to plot environmental impact per unit of product against yield for the beef, dairy, wheat and rice sectors. This produced data from modelling and field trials and the lifecycle assessment and field trial literature. The data were modelled statistically to adjust for differences between the studies. Given data limitations, it does not seem that higher yielding agricultural production has higher impacts, often quite the reverse. We ask those conducting field studies to collect data that can definitively answer this question.