Another related thing is the nutritional value info box that every food item in the US is required to have. That's a good thing in itself, except the US allows this info box to show the values "per serving", which is usually a completely arbitrary measurement, making it impossible to compare two food items to determine which has more sugar, or which has more protein.

In the EU, the same thing exists, but it is always per 100g or per 100ml. No exceptions. So comparing two food items is always super easy. I don't know why the US allows this idiotic loophole of per serving.