Marc Bellemare and colleagues at the University of Minnesota have an important new paper out on food waste.
First, they note that there are important weaknesses and inconsistencies in the leading definitions of food waste published by the United Nations, the USDA, and the European Union. Second, they provide compelling conceptual reasons to suggest that reported measures of food waste are almost certainly overstated. Finally, they propose a conceptual logically-consistent approach to measure food waste.
The arguments for why the value of food waste is overstated boil down to two factors: 1) some "waste" has productive uses as animal feed, compost, etc. and 2) the value of wasted food is often "priced" at the retail level, when in fact the actual waste occurs further upstream the supply chain where commodity prices are lower.
You can read the whole paper here.