Why Calorie Counts on Foods are Unscientific and Misleading

Описание: Calorie counts have been heavily emphasized in public health messaging in the US, and the issue has intensified in recent years when the counts have been presented in large bold lettering on newer nutrition labels.

I find the emphasis on counting calories harmful, as it is unscientific and misleading. The way energy intake works in the digestive tract and body is a lot more complex than the calorie counts suggest. I give three examples of common ways in which the calorie absorption from foods can vary hugely:

Mechanical processing of food, which can be both a function of the food being cut or ground vs. being whole, and also a function of how well you chew it. I give the example of flaxseeds as an illustration of an extreme case where you might absorb none of the calories at all if you eat whole flaxseed and swallow them without chewing.
Factors that speed up passage of food through your digestive tract, using the extreme case of diarrhea, which can result from many factors such as food poisoning, infection, or irritants in food. If food passes through your GI tract too fast, calories won't be fully absorbed (or absorbed at all).
Fiber, which has complex influences on calorie absorption. I explain that although fiber is usually considered calorie-free and is not included in calorie counts on labels, the body can actually indirectly absorb calories through food through absorbing byproducts (such as butyrate) of fermentation of the fiber by gut bacteria. On the other hand, fiber can also block the absorption of certain fats, thus reducing calorie absorption. So fiber can produce means through which your body either absorbs more energy or less than is reported on food labels.

These are only a few of many factors; I hope they illustrate how actual energy absorbed is more complex than the theoretical calorie counts on food. I explain how the gut is so complex that it is a bit of a black box.

For these reasons I don't think it is beneficial for most people to focus on calorie counts. If you are trying to lose weight (or gain it) I think there are better ways to approach food.

For weight loss I recommend focusing on whole foods, and in particular seeking out foods that are high in fiber, and also high in protein and micronutrients. I give whole grains, beans, nuts, and seeds as examples of such foods. I point out that nuts are often maligned due to their high calorie count, and use them as a prime example of how calorie counting can often lead people astray when they are trying to lose weight, as there is abundant evidence that eating nuts can help people lose weight.

I call for us to stop emphasizing calories so much in society, both in how we talk about food, and on nutrition labels. I would really like to see an end to the bold, large text for calories on food labels.