Depends on the amount you ate. The whole jar at one sitting is not a good idea. A t. or so for a snack will fill you up (but so will a cup of broccoli). Nuts are very fatty (peanut, soy, coconut, almond, chashew, etc. oil) and high in calories.
Question does not say it all. Calories in < less than calories burned = weight loss.
More likely to gain weight. Peanut butter is fatty, but high in protein. It is still healthy, but better consumed with a muscle building routine, and muscle building typically increases weight. So probably avoid peanut butter.
Or rub it on your face.
Ummm, peanut butter is loaded with fat (good fat) and sugar, usually. It is an awesome source of protein though. I love it! I suggest taking a big spoonful, enjoying it, then take a brisk walk around the block a few times.
Peanut butter is high in caories (with nutritional value,)
processed bread is high in empty calories. If I were going to add foods to loose weight I would add fruits and vegetables, at least 5 cups a day. They will fill you up and leave less room for higher calorie foods.