How To Calculate Calories From Carbohydrates (Carbs) - Fiber And Sugar Alcohols Explained

In this video we go through a detailed way to calculate the amount of calories from carbohydrates, including calories from fiber and calories from sugar alcohols.

Transcript/notes
Calories from carbs
When it comes to calories from carbohydrates, to make things easier, we need to break down carbohydrates into 3 different types, regular carbohydrates, fiber, and sugar alcohols. Let’s go through each of these.
Here is an example nutrition facts label. For 1 serving size, we see for total carbohydrates, it lists 17 grams.

This 17 grams of total carbohydrates includes regular carbohydrates, fiber and sugar alcohols. To find the number of regular carbohydrates, we need to deduct the 6 grams of fiber, and the 6 grams of sugar alcohols that the label lists.

Regular carbohydrates provide 4 calories per gram. So, the formula to calculate the number of calories from regular carbohydrates is, calories from regular carbohydrates equals, the quantity, total grams of carbohydrates minus grams of fiber, minus grams of sugar alcohols, times 4.

From our example nutrition label we have, 17 grams, minus 6 grams, minus 6 grams, equals 5, so 5 grams of regular carbohydrates. 5 grams of regular carbohydrates times 4 calories per gram equals 20 calories. So, we have 20 calories from regular carbohydrates.

Now for fiber. Fiber is a type of carbohydrate that is not digestible in the way other regular carbs are digested. And, there are 2 types of fiber, soluble fiber and insoluble fiber. Insoluble fiber does not provide any calories, however, soluble fiber is broken down by bacteria in the large intestine and does provide some calories. Soluble fiber provides about 2 calories per gram.

In most cases on nutrition labels, the total amount of fiber is listed, not the amount of soluble and insoluble fiber. So, it is usually a good idea to just assign 2 calories per gram of fiber, to be safe.

On our example label it lists the fiber at 6 grams, so, we just multiply that 6 grams times 2 calories per gram, which equals 12 calories from fiber.
Now for sugar alcohols. Sugar alcohols are a type of carb that contain 0 to 3 calories per gram, depending on the type of sugar alcohol. To make it easier to calculate, just estimate 2 calories per gram of sugar alcohols.
On our example label it lists the sugar alcohols at 6 grams, so, we just multiply that 6 grams times 2 calories per gram, which equals 12 calories from sugar alcohols.

One note, sugar alcohols are not required to be listed on food labels unless a statement is made on the package labeling about the health effects of sugar alcohols or sugar. If there is no listing for sugar alcohols then just ignore calculating them.

Now we can add up the total calories from all of the carbohydrates. We have 20 calories from regular carbohydrates, plus 12 calories from fiber, plus 12 calories from sugar alcohols, which gives us a total of 44 total calories from carbohydrates.

The complete formula for total calories from carbohydrates is, total calories from carbs equals the quantity, total grams of carbs minus grams of fiber, minus grams of sugar alcohols times 4, plus grams of fiber times 2 plus grams of sugar alcohols times 2.

One other note. The data listed on the nutrition label is always for a serving size. If our example label was for say for chocolate candies and the serving size was for 2 pieces at 25 grams, and we ate 3 pieces, we would have to adjust for that. To do that we would divide the number of pieces we ate by the serving size, which is 1.5, then multiply that number of 1.5 by the calories we calculated for 1 serving size, which I have done on the screen.

The main point is to always look at the serving size, and make the appropriate calculations for the calories.

Timestamps
0:00 Types of carbohydrates for calories
0:12 Example nutrition label
0:26 How to calculate calories from regular carbohydrates
0:38 Formula for calories from regular carbohydrates
1:11 How to calculate calories from fiber
1:56 How to calculate calories from sugar alcohols
2:34 Calculate calories from all types of carbohydrates
2:49 Complete formula for calories from carbohydrates
3:07 Serving sizes and calories