Jar of natural peanut butter vs. ice cream?

I've got an interesting story/question: I'm a 20 yr old male, 152 pounds, and I've been running marathons for about two years now (was pushing 230+ before I started running 3-4 years ago). I eat really "clean" now-free range meats, all kinds of nuts for fat, steel cut oats/quinoa/bananas/sweet potatoes for the insane amount of carbs I need, and usually at least 15-20 servings of vegetables and fruit (usually about 6 pieces or servings of fruit, and absolutely immense amounts of vegetables both fresh and frozen.

Anyway, I'm currently cutting 200-300 calories a day (basically just that extra big bowl of rice or oatmeal with dinner) to lose some of that winter weight that I put on from lower running mileages to get ready for some really good training. Thursday night, I wound up eating 1/2 a cup of organic, stir and refrigerated type peanut butter. Afterward, I didn't feel at all guilty or bad afterward, and my run today was fantastic. The scale only went up by like .2 pounds for one day (back to normal today), and looking in the mirror I don't look any different.

I kept having the thought the next day, "damnit, I could've had a pint of ice cream instead!". Anytime I eat sweets though, I feel like crap the next day and I'm incredibly bloated...which I guess explains why I don't feel guilty? My question is: is there a true difference between cheating on a diet with a bunch of peanut butter (I absolutely love it) and a pint of ice cream as far as body composition/general health goes?