Peanuts are actually low-carb, me thought. The lowest carb, as is a legume as Resurgam says, and not actually a nut. But what a legume - yum! I didn't eat them when paleo-ing, and had a giggle when on LCHF when I discovered that they are way lower carb than pistachios, which I love too. (Neither peanuts nor nuts spike me, negligible effect if any on BGs.)
Trouble with peanuts is, like popcorn (a whole other carb story!) you can keep eating them and eating them. I think they have a low satiety factor, why I have no idea.
Macadamias on the other hand - very yum, very low-carb (but not as low as peanuts), and super filling. Indeed. I cannot eat more than five or six small tasty Kiwi-macadamias at one sitting. (The 'Kiwi' refers to NZ, not to the fruit!) (I'm very envious of Tipetoo having macadamias growing next door...)
All the peanut butter I have is just ground peanuts. Absolutely no palm oil. Again, peanut butter a no-no in Paleo diet cos it's a legume (for apparent affect on digestion reasons), and why I got into almond butter. But peanut butter is lower carb. I eat both now, according to taste, no worries.