You have surely heard this before and likely followed it religiously. It sounds so simple, so elegant … but it is so wrong. It is increasingly clear that “a calorie is a calorie” is misleading — the evidence points primarily to the carbohydrate content of dietary intake rather than total caloric intake as the primary factor in body mass changes. Art De Vany covers this in-depth in his book The New Evolution Diet as well as in a series of posts on the topic summed up in his conclusion:
Turning to carbohydrates, a more helpful message than “eat less,” may be “eat less refined carbohydrates and more whole foods,” according to a recent article in the New York Times blog that synthesizes the latest research on the topic. Processed, refined carbs affect the brain in ways that other foods do not, even if their calorie count is the same:
The difficult aspect when it comes to making recommendations (or refuting the argument you have no doubt heard from a friend about their uncle who ate bagels and pasta all his life and never gained a pound …)? Not everybody who eats processed carbohydrates develops uncontrollable food cravings. But for the person who has been struggling with weight in our modern food environment and unable to control their cravings, limiting refined carbohydrate may be a logical first step.
The latest study tested subjects with high-glycemic shakes vs. a control group. What they found was that four hours after drinking the high-glycemic shake, blood sugar levels had plummeted into the hypoglycemic range; the subjects reported more hunger; and brain scans showed greater activation in parts of the brain that regulate cravings, reward and addictive behaviors. Although the subject pool was small, every subject showed the same response, and the differences in blood flow to these regions of the brain between the two conditions “was quite substantial,” according to the study’s directors.
Previous research suggests that when blood sugar levels plummet, people have a tendency to seek out foods that can restore it quickly, and this may set up a cycle of overeating driven by high-glycemic foods.
Is “a calorie a calorie”‘ dead as a nutritional guiding principle? Probably not for a long time. But the science is starting to unravel it as a legitimate basis for nutrition and wellness.