Foreign investors have acquired approximately 90 million hectares of land for agriculture over the past two decades. The effects of these investments on local food security remain unknown. While additional cropland and intensified agriculture could potentially increase crop production, preferential targeting of prime agricultural land and transitions toward export-bound crops might affect local access to nutritious foods. We test these hypotheses in a global systematic analysis of the food security implications of existing land concessions. We combine agricultural, remote sensing, and household survey data (available in 11 sub-Saharan African countries) with georeferenced information on 160 land acquisitions in 39 countries. We find that the intended changes in cultivated crop types generally imply transitions toward energy-rich, but nutrient-poor, crops that are predominantly destined for export markets. Specific impacts on food production and access vary substantially across regions. Deals likely have little effect on food security in eastern Europe and Latin America, where they predominantly occur within agricultural areas with current export-oriented crops, and where agriculture would have both expanded and intensified regardless of the land deals. This contrasts with Asia and sub-Saharan Africa, where deals are associated with both an expansion and intensification (in Asia) of crop production. Deals in these regions also shift production away from local staples and coincide with a gradually decreasing dietary diversity among the surveyed households in sub-Saharan Africa. Together, these findings point to a paradox, where land deals can simultaneously increase crop production and threaten local food security.

在过去的二十年里，外国投资者已经获得了大约 9000 万公顷的农业用地。这些投资对当地粮食安全的影响仍然未知。虽然额外的耕地和集约化农业可能会增加作物产量，但优先选择主要农业用地和转向出口型作物可能会影响当地获得营养食品的机会。我们在对现有土地特许权的粮食安全影响的全球系统分析中检验了这些假设。我们将农业、遥感和家庭调查数据（可在 11 个撒哈拉以南非洲国家获得）与 39 个国家的 160 次土地收购的地理参考信息相结合。我们发现，栽培作物类型的预期变化通常意味着向富含能量但营养贫乏的转变，主要用于出口市场的农作物。对粮食生产和获取的具体影响因地区而异。交易可能对东欧和拉丁美洲的粮食安全影响不大，这些交易主要发生在目前以出口为导向的农作物的农业地区，无论土地交易如何，农业都会扩大和集约化。这与亚洲和撒哈拉以南非洲形成鲜明对比，那里的交易与作物生产的扩张和集约化（在亚洲）有关。这些地区的交易也将生产从当地主食转移，恰逢撒哈拉以南非洲受调查家庭的饮食多样性逐渐减少。总之，这些发现指出了一个悖论，