FUN FACT: There is no legal definition for “net” carbs. Food manufacturers invented the term “Net Carbohydrates” in order to cash in on the low-carb craze and promise consumers that they could eat delicious treats without having to deal with the negative consequences of ingesting carbs. The ONLY information the FDA regulates is the information INSIDE the Nutrition Facts box which includes: Total Carbohydrates, Dietary Fiber, and Sugars.
The concept of net carbs is based on the principle that not all carbs are created equal – i.e. not all carbs affect your body in the same way. Some carbs, like simple sugars or refined starches (i.e. potatoes, white bread, and delicious donuts) are absorbed rapidly by the body and cause blood sugar levels to rise (in other words – have a high glycemic index). Eating an excess amount of simple carbohydrates lead to those calories being stored in the body as fat.
Other carbohydrates, such as the fiber, which is found in whole grain foods as well as fruits and vegetables, move slowly through our digestive system. Or in the case of insoluble fiber, isn’t digested AT ALL. (Want to know more about my thoughts on Carbs?? Check out this article: That Foul 4 Lettered C-Word: CARB)
Also, when we talk about “net carbs” we can’t leave out a huge category most of us see on our nutrition labels, ESPECIALLY when it comes to supplements, protein bars, and other diet or health foods – those “OTHER” carbs. “Other” carbs are made up of largely indigestible carbohydrates which are called sugar alcohols, such as mannitol, erythritol, xylitol, sorbitol, etc.. which are modified alcohol molecules that resemble sugar and are sugar replacements in foods (i.e. artificial sweeteners). Sugar alcohols are thought to cause less of a spike in blood sugar and have a lower glycemic index. They have about one half to one third less calories than sugar per gram. However, sugar alcohols aren’t all they’re cracked up to be – most people find that in large quantities (like in sugar free candies), sugar alcohols can cause a host of stomach issues including gas, bloating, and diarrhea. (What to know more about my thoughts on Artificial Sweeteners?? Check out this article: Take it from a Chemist: What are all those big names doing in my snacks and supps? AND What really *IS* healthy?)
Grams of dietary fiber are already included in the total carbohydrate count on nutritional labels. NET carbohydrates are the grams of TOTAL carbohydrates in a serving of food minus its grams of fiber AND other carbs. Because both fiber and other carbs are carbohydrates that your body cannot digest, and therefore do not raise your blood sugar levels or trigger an insulin response like (for the sake of argument) ‘normal’ carbohydrates.
SO… Big question here??? Should you count total carbs or net carbs? Well, it all depends on what your goal is and how sensitive to carbs you are. There’s no “wrong” approach to carb counting. Regardless of what you decide, I urge you to focus on QUALITY carbohydrates such as sweet potatoes, brown rice, and whole grains instead of quick fix carbs such as refined foods and sugars.