Flickr/anasararojasCalories are stupid.
Or, put more elegantly, they're not a very good measure for understanding how much energy is stored in food, and consequently, how much energy you need to expend in order to lose weight relative to what you eat.
The science is complex, and it's hard to know just how many calories you're absorbing whenever you eat something.
One thing that nutrition scientists have discovered: food has a lot of potential energy to give, but it doesn't all get to you. The more broken down a food is (as in, the more that it is cooked or processed), then the more energy gets to your body.
"Cooking unlaces microscopic structures that bind energy in foods, reducing the work our gut would otherwise have to do," report Cynthia Graber and Nicola Twilley. "It effectively outsources digestion to ovens and frying pans."
The implication for dieters: don't eat foods that come predigested by ovens or frying pans. Eat raw.
You can see evidence of this in nuts. According to Graber and Twilley's reporting, raw walnuts actually deliver 33% less calories to the body than would be listed in the nutrition facts. For walnuts, that's 21%.
For that same reason, it's crucial to stay away from processed foods. Since they're made of gunk that's been made into cookie or chicken shapes, all those calories have been predigested by the industrial food process, so they deliver the maximum caloric load to your body.
Which is both gross and fascinating.