Concern over carbohydrates has increased in recent years due to the popularity of Atkins and other carb restricted diets. While highly restrictive diets are not as popular as they once were, low-carb foods appear to be more popular than ever. This has led companies to label products showing the number of “net carbs” to attract carb conscious eaters. However, as with the term “low carb,” there is no government approved definition of a net carb.
There is also not a standard for how to calculate the grams of net carbs, which naturally leads to some confusion. Fortunately, there is an unofficial consensus about what constitutes a net carb. The net carb value is meant to represent the grams of carbs contained in a product that will impact your insulin levels (cause levels to increase). This is important, because higher increases in insulin result in more fat storage.
The typical approach to calculating net carbs is to take the total carbohydrate content and subtract fiber, sugar alcohols, artificial sweeteners, and any other carbohydrates that are not fully digestible. Then, any carbohydrates left over are considered net carbs. Products with lower net carbs are promoted as being better for losing fat or preventing fat gain and while there is some truth to this concept, it has some major flaws.
Net carb labeling tries to make it simple for people to count carbs, but incorrect assumptions are made that all net carbs are created equal and that all carbohydrates not counted as net carbs are good to eat. The fact is different net carbs affect your insulin level to different degrees and some net carbs will stimulate fat gain much less than others. Just looking at the number of net carbs simply does not give you enough information.
As for the carbs that are removed from the net carb calculation (fiber, sugar alcohols, etc.), they are noteworthy as well. Sugar alcohols (sorbitol, maltitol, isomalt, xylitol, etc.) are only partially broken down by the body, so they are not supposed impact insulin levels.
The problem is that anything that cannot be broken down still has to be processed and removed from your body. Many people find that consuming significant amounts of sugar alcohols results in an upset stomach or other intestinal issues. In addition, some people still experience insulin responses and feel fatigued or “crash” after consuming sugar alcohols.
Artificial sweeteners are different, because they have essentially no calories, but even they can cause an insulin response. The trouble with these ingredients is they often result in negative physiological reactions, such as feeling run down, not being able to think clearly, or getting headaches. If you have noticed similar reactions yourself, try natural sweeteners, such as stevia instead.
Fiber, on the other hand, is a carb you should make an effort to eat. Soluble fiber slows the absorption of food, which improves (decreases) your insulin response and it helps lower cholesterol. Much of the fiber in foods is insoluble, which does not really affect insulin, but it is still healthy, because it improves intestinal health, prevents constipation, and may help prevent some types of cancer. Most people do not eat enough fiber and increasing your intake can improve both your health and your ability to lose fat.
As you can see, net carbs and carbohydrates in general can be rather complicated, especially when considering that different individuals may respond very differently to the same ingredients. When looking at all the information, it becomes clear that net carb labeling is really more of a gimmick than anything. Instead of focusing on the number of net carbs, the best thing to do is look at the quality of carbs contained in the foods you eat.
Most people find they are more successful with their health and nutrition when they focus on eating natural healthy foods with quality carbs in moderate amounts, as opposed to eating a lot of low carb foods loaded with artificial ingredients. It is also important to remember that carbs are only one component of food and the fat and protein content in food is just as important as the carbs.