I think the primary concern is the number of carbs in a whole avocado...you can blow a significant portion of your daily 20 carbs on a single Florida Avocado (27 carbs - 16.2 fiber = 10.8 ECC according to the Dr. Atkins' Carbohydrate Gram Counter).

But the same source lists Haas (California) Avocados at less than one-third of that (12 carbs - 8.4 fiber = 3.6 ECC).

So, as I need the boost in my HDL Cholesterol (and I really looove avocados), I tell myself that my Haas Avocado is the LC version of the permitted fruit (can you tell that "rationalizations" are my weak point?)

My guess is that the original prohibition was actually written knowing that Haas Avocados aren't always available in all areas of the country. BTW, watch out for the new avocado variety boasting "low-fat." I don't have the numbers, but I suspect the trade-off may be increased carbs!