40 cal or less per RACC (and per 50 g if RACC is small) (b)(2)Meals and main dishes: 120 cal or less per 100 g (b)(3)
Of course, the tricksy issue is that a RACC/"serving" is pretty ambiguous size.
An avocado has 227 calories in it, 167 calories per 100 grams, but only 50 calories "per serving". So that means you get to eat 1/5 of a medium avocado per sitting to keep it within the official serving size.
But even with that serving size, 50 > 40, and 167>120 this is not a "low calorie food". Read your labels, but also use your brain!
That said, avocados are a pretty good for you food. They got fiber, they got fat, they have all the sorts of micronutrients expected from fruits and veggies. The vegetarians like them, the low omega-6 eaters like them, the glycemic index folk like them, the alkaline diet folk like them, even the guy that thinks we should eat chlorophyll and absorb sunlight recommends them (and the avocado is probably why his followers are still alive.) If you've got something against the avocado, you're in the minority.
So, have and avocado, but remember the calories count, it's not a free vegetable in your diet plan.