I went to a diet seminar given by a Yale cardiologist's registered dietician and she said that peanut butter is, anomalously, both one of the healthiest and unhealthiest foods in our society. This is because commercially processed peanut butters like Skippy, Jif et al have the much sought after peanut oil removed and then replaced with cheap, unhealthy oils like palm and cottonseed. She said commercially processed peanut butters like Skippy, Jif etc. rank at the top of her list as one of the unhealthiest things you can eat as far as cardiovascular health as it will really help block up the arteries.
She said natural peanut butter, on the other hand, is one of the healthiest things you can eat. Higher in monounsaturated fats and that is the key. I buy natural ground peanut and almond butters every week and they are certainly a healthy staple of any J Poucher's diet as a source of protein and good fat.
Just remember that in eating for your Pouch, you cannot forget about the rest of your body- namely your heart and arteries.