A CALORIE is a calorie. This truism has been the foundation of nutritional wisdom and our beliefs about obesity since the 1960s.
What it means is that a calorie of protein will generate the same energy when metabolized in a living organism as a calorie of fat or carbohydrate. When talking about obesity or why we get fat, evoking the phrase “a calorie is a calorie” is almost invariably used to imply that what we eat is relatively unimportant. We get fat because we take in more calories than we expend; we get lean if we do the opposite. Anyone who tells you otherwise, by this logic, is trying to sell you something.
I’ve been following this partly out of the normal scientific curiosity, partly out of personal interest — I’m not fat, but I worked in public health for years where they told people exactly this — and also due to some diet-related stuff I’ve been studying, not to mention the whole Paleodiet fad. At first I was kind of on the whole “carbs are the opposite of what we’ve been told” bandwagon that Taubes seems to be on, in part because a lot of human groups have survived (although how well isn’t known all that well, IMO) on a largely meat-based diet. For examples, use Inuit groups or Northwest coastal populations whose diets probably consisted almost 85% of marine protein sources, notably a LOT of salmon.
At the time I was associated with EMS, the Atkins diet was coming out and many of them (I was in a group primarily studying cardiac issues) were, to put it mildly, extremely skeptical. Mind you, of course, Taubes is looking at obesity, not other illnesses such as cardiovascular problems and diabetes for instance. But some other studies of Amerindian populations — and also recent immigrant populations, notably from east Asia — have suggested that diabetes and cardiovascular illness are correlated (strong caution there, obviously) with their adoption of more Western diets high in processed carbohydrates (white bread and Doritos, if you will). Some of these came from diets that were very high in animal protein (NW coast) and some from diets with high proportions of non-processed carbohydrates and little animal protein (e.g., east Asia and the Pima Indians for a classic example). Or even see the so-called French paradox.
So, I’m not convinced either that carbs are solely to blame for obesity, high cardiac mortality, or high diabetes morbidity. Or that the Paleodiet is the way to go either. OTOH, I’m convinced that the supposed “scientific consensus” of the past few decades has some major tweaking coming.