In other news, “The Hidden Truth about Calories” is both fascinating and, luckily, not just a rehash of other recent blogs and articles questioning the old wisdom “a calorie is a calorie.”
A digression: the old wisdom is that for weight loss all that really matters is calories in vs. calories out. Peddlers of magic diets promise us, instead, that not all calories are created equal, and then they point to low-carb, low-fat, or even low-protein (or high- carb, fat, protein) diets and dieters as evidence; but they’re rarely backed by sufficiently scientific studies, and they’re often marred by low-sample-size, self-reporting, lack of controls and blinds, etc. But, as promised, I digress.
The Scientific American blog post is a bit different: it’s not about protein vs. fat vs. carbs; it’s not about how a calorie is or isn’t a calorie. It is, however, a bit about the bioavailbility of calories. It’s both obvious and counter-intuitive in a way. The counter-intuitive part is only due, though, to how we focus on dieting, on losing weight, on reducing calories or burning more of them. This is such a recent “problem,” a so-called “first world problem,” one might say. Too many nutrients? Too much food? Poor us! The other obvious part we often miss is something we take for granted: what is a calorie and how to we measure them? A brief answer is that a calorie is a measure of chemical energy, defined in units describing the amount of energy required to heat an amount of water one degree. How we might measure how many potential calories a substance contains (via burning it, weighing its component, where we know the calorie count of those components, etc.) does not, however, map 1-to-1 with how many calories our bodies can get from said food item, and the given blog post does a decent job of breaking this all down.
