Every so often I hit a blind spot. The one I'm bumping up against at the moment is the term "Macro" when referring to food. I've tried dictionaries and they know about Zen Buddhist "Macrobiotic" but I'm pretty sure that's not what people mean when they discuss Macros. Could someone point me at a noteworthy online definition? Are essential amino acids or salt Macros and if not, why not? Is Macro just a shorthand synonym for "Fat, Protein and Carbohydrate"?