Two billion people currently suffer from micronutrient deficiencies. Existing literature shows that forests can improve people’s dietary quality—yet forests are often overlooked in food security policies, which focus primarily on the production of staple crops. The Bonn Challenge has set a goal of restoring 350 million ha of forest by 2030, but it remains unclear whether restored forests will exhibit the species diversity needed to improve diets in the same way as existing forests. Here, we report how forest regrowth in Nigeria has affected people’s dietary quality. We combine a new map on forest regrowth with food consumption panel data from over 1100 households—and use a combination of regression and weighting analyses to generate quasi-experimental quantitative estimates of the impacts of forest regrowth on people’s food intake. We find that people living in areas where forest regrowth has occurred have a higher intake of fruits and vegetables and thus higher dietary diversity.