Do Fibers Count as Calories and Carbohydrates?

Nutrition facts and measure tape

We all know the importance of balancing the number of calories we eat with the number of calories we burn to help achieve and maintain a healthy weight. The number of devices that estimate how many calories you burn and the apps that help you estimate how many calories you are eating can certainly help keep us focused on our goals, but many of us start to wonder about the calculations and what else we can do to achieve our goals.

For those of us who manage our diet by counting calories or counting carbohydrates, confusion regarding fiber may arise as some people say that fiber has no calories while others say that each gram of fiber provides 4 calories. The same confusion exists when you ask if people count fiber as a carbohydrate or not. This confusion should not be a reason to avoid eating enough fiber since it is universally agreed that fiber provides many health benefits, including helping a person feel full and reducing over-eating. Below is some information to help you understand calorie and carbohydrate counts for fiber.

Fiber and Calories

Determining whether or not fiber calories should “count” depends on context and requires some background. Calories are a basic unit of energy that measure, among other things, how much burning power they provide to the body. Fats, proteins, carbohydrates and alcohol provide the body with energy or calories. The traditional estimates are that 1 gram of fat provides 9 calories, each gram of either proteins and carbohydrates provide 4 calories, and a gram of alcohol provides 7 calories. However, this doesn’t account for differences in how well food is digested and the nutrients available to the body. Poorly digested foods may not release as much energy for the body to use. This is particularly important in the case of fibers.

Dietary fibers are complex carbohydrates, so some people estimate that they provide 4 calories per gram just like any other carbohydrate. However, others say that calories from fiber don’t count since your body’s digestive enzymes can’t break down fiber. However, fibers differ in how well they are digested or how much energy is available to the body. Some fibers, called soluble fibers, either absorb water and become gels or dissolve in water and reach the intestine where they are digested by bacteria. As they are digested by bacteria, soluble fibers produce short-chain fatty acids (SCFAs) that provide your body energy. The US Food and Drug Administration (FDA) estimates that fibers fermented by bacteria provide about 2 calories per gram of fiber. Insoluble fibers travel to the intestine with very little change. Instead of being digested, insoluble fibers increase bulk, soften stool, and shorten transit time through the gastro-intestinal tract.  Because these fibers are not digested at all, the FDA estimates that insoluble fibers do not contribute any calories.

Rather than worrying about the accuracy of calorie-counting and the relatively small differences in calorie estimates contributed by the fiber in your diet, it may be best to focus on eating the recommended amount of fiber each day, which is 14 grams of fiber for every 1,000 calories. For those that adhere to their diet by tracking calorie balance, it may be better to count the calories from fats, proteins, total carbohydrates and alcohol and try to increase physical activity to burn more calories since these are activities you can modify.

Fiber and Carbohydrates

Regardless of whether someone is counting carbohydrates because of a carbohydrate-based diet plan or to manage insulin doses, there is some confusion regarding whether or not fibers should be counted as carbohydrates. Carbohydrates such as sugars and starches are energy sources that the body can quickly convert to fuel and require insulin. While fibers are carbohydrates, they do not affect your body’s sugar/glucose levels or the levels of sugar related hormones such as insulin. In fact, high fiber meals take longer to digest and therefore, affect your blood glucose more slowly. This is why it is often recommended that individuals calculating insulin needs should subtract fiber from the total carbohydrates of a food. Therefore, it is often advised that individuals following a carbohydrate-based diet plan not count dietary fiber as a carbohydrate.