**1.2 What is food system sustainability?**

Food system sustainability is a complex topic that spans aspects all along the supply chain, from on-farm growth of crops by agricultural producers, ingredient preparation and product processing by food manufacturers, the selling of food products by retailers, and the consumption of food by consumers and the food service industry [1]. Sustainability can be addressed from multiple aspects, including sustainable agricultural practises to optimise crop yield with minimal inputs, the substitution of existing food ingredients with sustainable alternatives, optimised efficiency of food manufacturing processes, reducing food waste, and promoting social sustainability through food security and equity considerations.

A key opportunity to enhance food system sustainability is through addressing food loss and food waste. Food loss refers to a reduction in food production due to preconsumer losses that occur all along this supply chain from harvest, post-production, storage, transportation, primary processing and wholesale. Recent estimates from the Food and Agriculture Organisation of the United Nations (FAO) stating that around 14% of global food production is wasted before reaching the retail market [2]. On the other hand, food waste refers to the disposal of food that is fit for human consumption. The United Nations Environment Programme (UNEP) estimates that an additional 17% of global food production is wasted in retail and consumer settings [3].

**Figure 1.** *Scope of the book chapter.*

Although a high level of investment is dedicated toward agricultural research, greater than 90% of this investment is targeted at optimising crop productivity, while approximately 5% of investment is aimed toward research to reduce food losses [4]. This is a significant misjudgement, as greenhouse gas (GHG) emissions embedded in the wasted food product increase as the product moves along the supply chain [2]. Addressing food waste can have significant environmental, social, and economic benefits. It can help to reduce GHG emissions, conserve natural resources, and increase food security. Additionally, reducing food waste can also help to save money for both businesses and consumers.
