Low fat or high fat foods, whats the diff?

Okay, so I'm curious; what is the difference if I eat 500 calories of NO fat foods over my recommended daily calorie intake, compared to if I eat 500 calories of fatty peanut buttery chocolaty fat foods over my daily intake? Will the NO-fat foods be easier to burn off the next day in exercise? Do the no-fat pounds fall off easier than the fat food pounds, or do they both take the same amount of exercise??