Phantom Carbohydrates – A Nutrition Mystery
How can a drink contain carbs but no calories? Find out how food companies can legally fudge the number of calories in their products.
Monica Reinagel, MS, LD/N, CNS
Listen
Phantom Carbohydrates – A Nutrition Mystery
John writes in with a nutrition mystery:
Q. I enjoy drinking SoBe Lifewater, which is sweetened with erythritol. The label says a serving contains 6 grams of carbohydrates but no calories. How can this be? Everywhere I look I see it stated that carbohydrates contain 4 calories per gram.
The answer to John’s mystery involves both science and deception. First, let’s tackle the science.
How Many Calories Are in Carbohydrates?
If you’ve dabbled around in nutrition for a while, you’ve probably come across the 4-4-9 rule, which says that a gram of either carbohydrate or protein will contain four calories while a gram of fat provides nine. However, the 4-4-9 rule is really only a very rough approximation. In fact, the exact number of calories in a gram of protein, carbohydrate, or fat varies quite a bit, depending on the food and how your body processes it.
Fiber, for example, is technically a carbohydrate—and it’s included in the total carbohydrate listed on the nutrition facts label. But, as you know, fiber is largely indigestible, meaning that it doesn’t provide much food energy. If a food is high in fiber, it will contain considerably less than four calories per gram of carbohydrate. The carbohydrates in wheat bran, for example, contain about 2 calories per gram.
Are Sugar Alcohols Calorie-Free?
Sugar alcohols, such as erythritol, maltitol, sorbitol, and xylitol are also considered carbohydrates and—like fiber—are included in the total carbohydrates on the label. (It’s easy to spot them in ingredient lists because they almost all end with –ol.) However, sugar alcohols don’t provide four calories per gram. For example, erythritol contains less than a half a calorie per gram; some of the others have up to 3. In any case, a food sweetened with sugar alcohols will contain fewer than four calories per gram of carbohydrate.
See also: What Are Sugar Alcohols?
But the presence of sugar alcohols doesn’t completely explain how a drink can contain six grams of carbohydrates per serving and still have no calories. As I said, there’s also some deception involved. Legal deception, that is.
When is a Calorie Not a Calorie?
When a food contains fewer than 5 calories per serving, the manufacturer is allowed to “round down” to 0 on the Nutrition Facts label
The truth is that despite what it says on the Nutrition Facts, this drink is not completely calorie free. Like most soft drinks, it comes in a 20-ounce bottle. However, the information on the nutrition label is based on an 8 ounce serving. In other words, each bottle contains two and a half servings—so you can share it with one and half friends, maybe?
If you look on SoBe’s website, you’ll see that a 20-ounce bottle contains 10 calories. Obviously, if 20 ounces contains 10 calories, then eight ounces will contain four calories. (And if that’s not clear, may I recommend The Math Dude’s terrific podcast?) And here’s where the perfectly legal deception comes in. When a food contains fewer than 5 calories per serving, the manufacturer is allowed to “round down” to 0 on the Nutrition Facts label.
Ten Calories Aren’t Worth Worrying About
Although this misrepresentation might be a little irritating, it’s really not that big a deal. Even if you drink the whole bottle yourself rather than enjoying it in two and half sittings, 10 calories is not a significant amount and probably not worth worrying about.
Of course, if you’re drinking 10 or 20 bottles a day, those phantom calories could start to add up. But you’d probably run into a different problem before you got to that point. Consuming large amounts of sugar alcohols can cause a collection of uncomfortable symptoms delicately known as “digestive upset.”
Are Vitamin Waters a Good Source of Nutrition?
Finally, a word about the nutritional value of vitamin- and herb-enhanced waters. If you simply enjoy the taste (and you stick with sugar-free), there’s little harm in enjoying them in moderation. However, if you’re justifying spending two bucks a bottle on the basis of some alleged health or nutritional benefits, you should know that scientific support for those would be even harder to find than the missing calories on the label.
Keep in Touch
Have you discovered phantom calories in your food or drinks recently? Let us know in Comments.
Send your burning nutrition questions to nutrition@quickanddirtytips.comcreate new email or post them on my Nutrition Diva Facebook Page. And be sure to sign up for my free weekly newsletter, where I share more tips, recipes, and answers to your questions.
RESOURCES:
Calculating calories from fat, carbohydrate and protein (Nutribase)
Image courtesy of Shutterstock
About the Author
Monica Reinagel is a board-certified licensed nutritionist, author, and the creator of one of iTunes’ most highly ranked health and fitness podcasts. Her advice is regularly featured on the TODAY show, Dr. Oz, NPR, and in the nation’s leading newspapers, magazines, and websites. Do you have a nutrition question? Call the Nutrition Diva listener line at 443-961-6206. Your question could be featured on the show.