In this thesis, our primary objective is to assess the water usage associated with the losses and waste in staple crops, specifically focusing on identifying the countries most significantly impacted by the use of freshwater resources throughout the food value chain. The chapter "Food-Water nexus" serves as an introductory exploration of the intricate relationship between food and water. Within this chapter, we elaborate on the critical importance of minimizing water wastage and provide a comprehensive understanding of the concept of water footprint. Furthermore, we delve into an in-depth examination of food loss and waste, with a specific emphasis on elucidating the drivers and the impacts.