A critical analysis of challenges and opportunities for upcycling food waste to animal feed to reduce climate and resource burdens

Global food loss and waste has not abated despite tremendous efforts to reduce it. Food wastage has profound consequences including our inability to combat hunger, contributions to unsustainable resource exploitation, and represents about half of the greenhouse gas emissions of the entire agrifood system. Mitigating the problems for a sustainable future requires managing food waste using the most appropriate approach. Upcycling food waste to animal feed is an essential strategy to capture the greatest value compared with other recycling options. The overall goal of this critical analysis is to provide evidence that upcycling of many food waste sources to animal feed can be successfully achieved in support of sustainable productivity. We describe multiple dimensions of reducing emissions and improving resource utilization efficiency, characterize the suitability of various food waste sources and limitations as animal feed, and describe the needs for de-risking strategies, overcoming legislative bottlenecks, and filling knowledge gaps to accelerate greater use of this high impact sustainability strategy.