Deconstructing the myth of the calorie. Tl;dr, it’s busted as fuck, mostly because there’s no reliable, in-the-field, way of measuring how many calories are, a) in any one dish, and b) absorbed by any one human in the digestion processes.

Also interesting here is the description of the first experiment to measure a calorie (though it wasn’t defined as such at the time, circa 1780), which basically involved putting a guinea pig on a block of ice and counting how fast the ice melted, and thus how much heat the guinea pig was giving off, and thus how many calories it was burning.