• Thu, Aug 9 2012

Ok, But Seriously: There’s No Such Thing As “Zero Calorie Foods”

zero calorie foods myth

There are some health myths that just. Won’t. Die. But the one I hear repeated by intelligent, otherwise rational human beings is that some foods–celery, lettuce, and citrus fruits, among others–are “zero calorie foods.” Which means, legend has it, that you burn more calories eating them than they contain. But, unfortunately, that’s just not how the world works. That is simply incorrect. For the last time, it’s just not true. Sorry.

It makes logistic sense, theoretically, that a food which is mostly water and only has, say, 10 or 15 calories per serving, like lettuce, would be burned off quickly. Because, of course, in addition to chewing, your body also burns calories digesting and processing food. However, there are a few holes in this theory.

The first major flaw is that chewing actually takes basically no effort and burns almost no calories at all. In fact, for all intents and purposes, just consider it to be as low impact as, say, breathing. Or watching television. It’s just a bodily function, and you get no points for it. Don’t believe me? Borrow a fitness tracker (like a BodyFIT Media or FitBit) from someone, if you know such a person, and walk in place until you’ve burned 10 calories. It will feel like a lifetime.

The other big problem with the theory of zero calorie foods is that it’s mathematically double-dipping. Calories aren’t exactly a hard-and-fast science with one exact answer–just think about what we learned about almonds this week. And to calculate the calories in a food, lots of things are taken into account…including the amount of effort it takes to eat and digest the food. These are the calories that are “wasted” in the eating process. So if you consider a food to be “zero calorie,” you’re counting mastication and digestion twice. Which, in finance, is considered fraud. It is similarly wrong when it comes to nutrition.

Which isn’t to say that celery, lettuce, or other “zero calorie foods” are useless or bad–that’s obviously not the case. These foods are high in fiber, which is great for your digestion, and full of nutrients, while still remaining low in (but not devoid of) calories. Watermelon, for example, is a great summer snack, because it’s hydrating and healthy, without being high in fat or calories.

However, the point is that assuming that any food is “free” or “zero calories” isn’t really taking a holistic approach to your health and diet. Instead of trying to cheat around eating healthy by eating foods that supposedly burn calories, why not eat filling, nutritious foods (caloric or otherwise), and then burn them off with exercise?

Oh, and don’t forget to show this article to everyone you know who ever dares repeat this myth. You are charged with helping to set the record straight.

Image: TheDeliciousLife on Flickr

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  • Amy

    Great article and I think you make a great point in saying “assuming that any food is “free” or “zero calories” isn’t really taking a holistic approach to your health and diet.”

    It’s so true, yes we all understand that counting calories is generally helpful in taking notice of what we’re eating, but we should also be focusing on the nutritional content of those calories and whether or not they are good for us (100 calories of red peppers) or not beneficial for us (100 calories of potato chips) at all.