What Does Low-Carb Really Mean?

FDA will soon weigh in on low-carb food and beverage claims.

5 min read

Are you craving chocolate, but trying to stick to a low-carb diet? No problem. A flood of "low-carb" treats from beer to pasta and even candy has hit supermarket shelves in recent months to fulfill the cravings of dieters who are counting carbohydrate grams rather than calories.

With claims such as "low-carb," "reduced carb," and "carb-smart," these products promise to help Atkins and other low-carb diet devotees stay true to their weight-loss plan while satisfying their hunger for traditionally high-carb foods.

But is a low-carb beer any better for you than the regular version? What does low- or reduced-carb content really mean?

That's where experts say the marketing is way ahead of the science. Unlike "low-calorie" or "reduced-fat" claims, the FDA has not legally defined what "low-carbohydrate" means.

Next week, the agency will finally weigh in on the low-carb debate when its Obesity Working Group presents a report to the FDA commissioner on Feb. 12. The group is expected to recommend stricter labeling requirements to help consumers make smarter food choices.

Industry and consumer groups have called on the FDA to not only provide a definition for low-carb claims but also address the use of implied low-carb claims and "net carb" counts on product labels.

"People assume that they can't gain weight on foods with claims like 'carb-aware' and 'carb-smart,' just as they assumed that 'fat-free' on the package meant 'fat-free' on your waist," says Bonnie Liebman, nutrition director of the Center for Science in the Public Interest (CSPI), in a news release. "It's a huge leap of faith to assume that the calories in a lower-carb food don't count."

According to Institute of Medicine, the organization that sets the recommended daily intake of nutrients, adults and children over the age of 1 should eat 130 grams of carbs a day.

However, not surprisingly, most people exceed this daily amount. Depending on age, the IOM says that men typically eat about 200 to 330 grams of carbs a day while women eat around 180 to 230 grams daily.

Carbohydrates are the brain's primary fuel source and the daily minimum requirement is based on this need. The Institute notes that people following an extremely low-carb diet may not be getting enough daily carbs.

Experts say that until the FDA takes a stand on the carbohydrate issue, it's up to consumers to educate themselves on how to interpret low-carb claims on product labels. By law, food manufacturers are required to list the number of total carbohydrates in a product on the nutrition facts label. But makers of low-carb products often include another box next to the nutrition label that has information on the "net carb" content of the food.

The net carbohydrate content is designed to reflect the amount of carbohydrates the product contains that will cause blood sugar levels to rise, a key factor in low-carbohydrate diets such as Atkins.

"There is no legal definition of net carbs. That's their math," says Larry Lindner, an instructor at the school of nutrition science and policy at Tufts University in Boston. "They have a formula about how the number of grams of carbs don't count the way you think they would count."

Registered dietitian Samantha Heller says that in calculating the net carbohydrate content, many food companies subtract the number of grams of dietary fiber as well as other carbohydrates such as glycerin and sugar alcohols from the number of total carbohydrates listed in the nutrition facts label.

"Their rationale is that the glycerin and the sugar alcohols do not raise blood sugar as quickly or as high as the regular carbohydrates," says Heller, who is a senior clinical nutritionist at New York University Medical Center. "Though this is true, they're choosing to ignore the fact that they still have calories."

For example, Lindner recently compared a sampling of low-carb products with their "regular" beer counterparts. He found low-carb beers often contain virtually the same number of calories, despite the much higher price tag.

His study showed that a 12-ounce bottle of Michelob Ultra Low Carbohydrate has only one less calorie and about half a gram fewer carbohydrates than a bottle of Miller Lite, which has 96 calories and 3.2 grams of carbohydrates. But the low-carb version costs 12% more than standard light beers.

In comparison, regular beers typically contain about 150 calories and more than 10 grams of carbohydrates per serving.

Rather than relying on the manufacturer's math, Heller recommends that carb-conscious consumers look at the total number of carbohydrates in the nutrition facts label and then subtract only the dietary fiber in order to get an idea of how many net carbohydrates are in the product.

Unlike sugar alcohols, Heller says dietary fiber does not make a significant contribution to the calorie content of foods because the body does not digest it.

Despite the popularity of low-carb products and diets, nutritionists say America's obesity epidemic shows no signs of waning, and the low-carb craze may play out the same way the low-fat frenzy did a decade ago.

"During the low-fat craze, people ran out and bought low-fat Snackwell cookies," says Lindner. "Well, guess what? They have the same number of calories as Oreos and Chips Ahoy, and you're not going to lose weight if you keep eating those. It's the same thing with the low-carb products. They essentially have as many calories as the things they are meant to replace, and you're not going to lose weight if you don't eat fewer calories."

Heller agrees and says winning the battle against the bulge isn't about replacing one source of empty calories, such as beer, with another lower-carbohydrate version. Instead, it's about making healthy lifestyle changes.

"You can lose weight by eating healthy food or unhealthy food," Heller tells WebMD. "We would prefer, and your body would be happier, if you were trying to reach and maintain a healthy weight by eating healthy food."