Food Waste
Food waste refers to the food that is not consumed and is discarded or otherwise lost throughout the entire food system.
Source: Wikipedia
Image Source: TABLE
Food By-Products
Food by-products refer to the secondary products derived from food raw materials, but this does not mean they have no value.
Source: AAFCO
Image Source: EFSA
Although the two are not exactly the same, both of them may represent the overlooked and lost value, rather than just "useless leftovers".
Why does so much get lost and How does this relate to food security?
Food by-products and food are usually lost and wasted at different stages of the food system, such as during storage, during production, as processing leftovers, due to quality issues, and as a result of consumer behavior. Waste leads to inefficiency in the food system and affects its resilience, weakening the food system's ability to support food security and further impacting food security.
Image Source: ORF
Why is the issue of waste worthy of attention?
Video Source: YouTube