Hi everybody this is Monica Reinagle. Welcome back to the nutrition

divas quick and dirty tips for eating well and feeling fabulous.

John writes in with a nutrition mystery. He writes, I enjoy drinking soby life water

which is sweetened with erythritrital. The label says a serving contains six grams

of carbohydrates but no calories. How can this be?

Everywhere I look I see it stated that carbohydrates contain four calories per gram.

Well the answer to John's mystery involves both science and

deception and we'll start with the science.

If you've dabbled around a nutrition for a while, you've probably come across the 449 rule, which says that a gram of either carbohydrate or protein will contain 4 calories, while a gram of fat provides nine.

However, the 449 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 that's 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 fewer than four calories per gram of carbohydrate. The carbohydrates in wheat bran, for example,

contain about two calories per gram. Sugar alcohols, such as erythritol, maltatol, sorbitol, and xylotol are also considered

carbohydrates and like fiber they're included in the total carbohydrate on the label.

It's easy to spot them in the ingredient lists because they

almost all end with O.L. However, sugar alcohols don't provide four calories per

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