Cotton!
Cotton, most peanut butters (i.e. anything that's not 'natural') have all the really AWFUL oils
that are full of trans fats!
Check your ingredients and see if the PB has the word "hydrogenated". If so, it's a trans fat. Yuck!
I know...it tastes good, but what it does to your body...
Try the natural kind...in the West, it's Laura Scudder's, in the East, it's Smucker's, that you can find easily in most grocery stores. There are other brands, though, so feel free to shop around and find one that you like. You are looking for one that has just peanuts and salt in it. Be very careful with anything else they add in...okay? The best, I've found, if you can get it, is freshly ground PB...it's amazing!
I used to get it at the Farmer's Market in L.A. Not only is it way fun to watch the ribbon of PB come out of the machine, but the taste is out of this world.
Glad to have you with us...this was a great question!