Upcycled Proteins: Reconceptualising Waste as a Sustainable Resource

The global demand for protein continues to rise amid intensifying environmental pressures and limited natural resources. Conventional animal-based proteins contribute substantially to greenhouse gas emissions and biodiversity loss, creating an urgent need for sustainable alternatives. This viewpoint article examines the potential of upcycled proteins as a strategic component of the circular bioeconomy. By converting by-products like rapeseed meal, broccoli biomass, and brewer’s spent grain into valuable food ingredients, upcycling helps retain nutrients, enhance food security, and lower environmental impacts. Yet, regulatory ambiguity, consumer perceptions, and challenges in scaling production remain significant constraints. Achieving broader adoption will require supportive policies, transparent labelling, and public–private collaboration. Reframing upcycling from “waste reduction” to “resource renewal” could also strengthen consumer confidence and stimulate market growth. Incorporating behavioural insight into innovation and policy frameworks will further enable inclusive and long-term engagement across the food sector. Overall, upcycled proteins represent a shift from linear to circular food production, integrating technological progress, policy support, and societal participation. As the global population approaches 10.4 billion, reconceptualising by-products as renewable resources offers both an ecological necessity and a viable pathway to sustainable nutrition.