hypothesis:
if 140 of 180 calories in natural peanut butter (just ground peanuts nothing added, maybe salt) come from fat, and you pour the inch of separated oil off the top upon opening, eating the stuff that's left is the equivalent of eating snow peas.
(disclaimer: i swear i don't count calories and i definitely don't count fat grams. i look at the food before me and say "did this grow on its own?" if so, i'll eat it. if not i'll say "did somebody i love make this?" if so, i'll eat it. if not i'll say "am i out to eat with somebody i love?" if so i'll eat it. if not i'll say "am i pmsing?" if so i'll eat it.)