Addressing the needs of older persons poses public-policy challenges. The obstacles that the poorest older persons face in securing their livelihoods, compounded by physiological and metabolic changes and the presence of chronic diseases, make them more vulnerable. This study evaluates the impact of the Continuous Benefit Programme (BPC) on the nutritional status and food security levels of older persons in Brazil, using a fuzzy regression discontinuity design with microdata drawn from the 2017–2018 Consumer Expenditure Survey (POF). On average, participation in the programme is found to increase the probability that an older person will be food-secure, and to reduce his/her chances of suffering mild food insecurity. Although the objective of the programme is to reduce poverty, these findings can support the formulation of public policies that promote the quality of life of older persons, by acting on purchasing power, health and nutrition.