Approximately one out of every four calories grown to feed people is not ultimately consumed by humans. Food is lost and wasted to a varying extent across the globe, across all stages of the food value chain, and across all types of food. As a result, overall global food availability is lower than it would be otherwise, negatively affecting food security and requiring the planet's agriculture system to produce additional food to compensate for the food that is not ultimately consumed by people. The potential benefits of reducing food loss and waste are large. As a strategy for closing the food gap between food available today and food needed in 2050 to adequately feed the planet's projected 9.3 billion people, reducing food loss and waste satisfies each of the development and environmental criteria we introduced in the first installment of the Creating a Sustainable Food Future series. While increasing food availability, reducing food loss and waste can alleviate poverty and provide gender benefits while reducing pressure on ecosystems, climate, and water. Reducing food loss and waste may be one of those rare multiple "win-win" strategies.How can the world go about reducing food loss and waste on a large scale? This installment of the forthcoming "World Resources Report Creating a Sustainable Food Future" addresses that question. This working paper, which will feed into that report, begins by clarifying definitions of food loss and waste, then quantifies the scale of the problem and explores the impact addressing the problem could have on the food gap. The paper then focuses on practical solutions for reducing food loss and waste and presents case studies of successful initiatives. It concludes by offering recommendations for how to scale up reductions in food loss and waste