Many Indigenous communities around the world have been experiencing rapid and profound diet changes. This Case Report uses a Sustainability Science lens to understand the characteristics of diet change in Indigenous Gunas communities of Panama, as well as its drivers and sustainability impacts. We observe the rapid westernization of diets mainly driven by modernization and development processes. However, this diet change has a series of intersecting sustainability impacts related to food security, health, and socio-cultural and environmental change. It is necessary to understand the intersection of these phenomena when designing programmes and interventions seeking to prevent or mitigate negative diet changes in Gunayala, and Indigenous contexts more broadly.