Calories and macronutrients on nutrition labels don't make sense

I have a theory, and I've been trying to track down whether or not it's true, and managed to find a slight bit of info here that could be a springboard for further searching. Basically, the 1 carb = 4 calories thing is oversimplified. Fiber is counted as a carb, but the body doesn't digest some fibers. Other fibers are broken down a bit by bacteria, and the USDA estimates you get about 2 calories per carb of that fiber.

I'd imagine other subsets of carbohydrates break down a bit differently, as well. Nothing the average consumer needs to know, but I trust the people creating nutrition labels to be calculating those nuances correctly for us laymen.

arieldawn9463 wrote: »

Example: the label on fiber one bran cereal claims it has 60 calories per half cup and 25 grams of carbohydrates. However, 1 gram of carbs = 4 calories, which means it should be 100 calories per half cup. This is confusing me, are nutrition labels not to be trusted? Is there something I'm not realizing that allows this to all make sense?

US labeling rules allow for companies to decide how they include fiber calories based upon the type of fiber. Items that focus on promoting their fiber content seem to be more likely to subtract those calories from the total listed calories.

Fiber is carbohydrate we cannot digest and therefore has no calories. So if a product has 15 grams of digestible carbohydrates like sugars or starches and then 10 grams of fiber it will have 25g of carbohydrate and 60 calories. It should list the fiber as well so if you subtract the fiber grams from the carbohydrates then the calories should sum correctly...no issue.