Invasive species can significantly disrupt environmental quality and flows of ecosystem services and we are still learning about their multidimensional impacts to economic outcomes of interest. In this work, I use quasi-random US county detections of the invasive emerald ash borer (EAB), a forest-attacking pest, to investigate how invasive-induced deforestation can impact obesity rates and time spent on physical activity. Results suggest that EAB is associated with 1–4 percentage points (pp) (mean = 37.0%) annual losses of deciduous forest cover in infested counties. After EAB detection, obesity rates are higher by 2.5pp (mean = 24.7%) and daily minutes spent on physical activity are lower by 4.9 minutes (mean = 51.7 min), on average. I show that less time spent on outdoor sports and exercise is one possible, but not exclusive, mechanism. Nationwide, EAB is associated with $3.0 billion in annual obesity-related healthcare costs over 2002–2012, equivalent to approximately 1.2% of total annual US medical costs related to obesity. Results are supported by many robustness and falsification tests and an alternative IV specification. This work has policy implications for invasive species management and expands our understanding of invasive species impacts on additional economic outcomes of interest.