How to feed the world is a vigorously debated question, but the extent to which possible solutions receive attention in the scientific literature has not been studied. Using textual analysis, we analyse 12,640 research articles to quantify how this discourse evolved over the last 50 years, distinguishing between a focus on three potential levers: total food production, per capita food demand, and population. We find a strong and increasing focus on feeding the world through increasing food production via technology, while the focus on reducing food demand through less intensive dietary patterns has remained constant and low. Population has declined from being the dominant lever discussed in 1969 to the least researched in 2018. Our results suggest that very few studies address all three levers in an integrated way, which may be constraining the solution space for feeding the world and meeting other Sustainable Development Goals.