There’s massive confusion about calories-in-calories-out (often abbreviated CICO), but it’s a fundamental weight-loss truth, so I’m going to try to clear it up. (And I hear you saying “Good luck with that.”)
Despite being all the same, the calories come in a food package, and there are lots of other things about food that can affect both the calories-in and the calories-out sides of the equation. The real disagreement isn’t over whether this is true; it’s whether the effect is large enough to make a difference in weight loss.
Hard-to-digest carbohydrates: While some carbs (think sugar) are easy for our bodies to break down, others (think lentils) are harder. Foods that are high in fiber and other digestion-resistant carbs, like oligosaccharides, and resistant starch don’t get completely broken down. They exit your body, if all goes smoothly, first thing in the morning.
Macronutrient content: Food is made of up of carbohydrates, fat and protein, and your body has to break all of those down to make the calories accessible. That breaking down takes energy (calories!). I think of this as digestive overhead, but scientists call it the “thermic effect of food,” and estimate that it’s about 10 percent of the calories you burn in a day.
Hormonal effects: Food can affect the hormones that regulate your metabolism. Low-carb diets, for example, hang their hat on the idea that, if you release less insulin (a hormone integral to fat storage), you cannot store fat, and your body will burn more calories.
There are undoubtedly other ways in which what you eat affects how many calories you absorb, many of which we have yet to discover. Of course, there’s also the issue of satiety; if what you eat helps you eat less later, you obviously absorb fewer calories. What all those effects have in common is that someone has tried to sell you a diet based on it.
I started off talking about all those ways that what we eat affect how we absorb or burn calories, but she dismissed them wholesale. “It’s trivial!” she said. “In studies where people were locked in metabolic wards, if the calories were lower, they lost weight at a predictable rate, regardless of the composition of the diet.” The diets, she said, “varied from 80 or 90 percent carbs to 80 to 90 percent fat.” And it just didn’t make much difference.
It’s absolutely possible to eat a diet of foods that make it nearly impossible to keep calories in balance. The Häagen-Dazs Diet. The Pepsi Diet. The Bacon Diet. But if you’re looking at reasonable permutations of whole-ish plant and animal foods, the percent of calories you get from protein and the grams of carbs you eat in a day are all but irrelevant for weight loss.
If you don’t believe me, or Nestle, I invite you to pop on over to PubMed, the repository of academic papers, and look around. Look at the meta-analyses, which try to make sense of the body of evidence, and find one where a particular kind of diet outperforms others long-term by more than a few pounds.
“Because you can’t see them,” she said. “And you also can’t count them.” You don’t know exactly how many are in your food, and you don’t know exactly how many of those you absorb, and you don’t know exactly how many you burn. But you can read labels, check calorie counts and venture a guess, and you have an infallible tool to find out if you’re right: “Weigh yourself on a scale,” Nestle said. If you’re not losing weight, you have to find a way to rejigger the equation.
This content was originally published here.
