I think in this case "food waste" is the food we purchase, but ultimately discard into the trash. For example, I always make 1 Lb of spaghetti at a time but my wife and I eat less than half of that for dinner. Then we each have "leftovers" for lunch the next day, and I still have spaghetti to throw in the garbage. Hell, theres probably 55 gallon trash cans full of food every day in @Hurlsnot school cafeteria.