Measurements in humans of their breath hydrogen is sometimes used to assess the availability, fermentability, and food energy value of carbohydrates that, to an unknown extent, resists small intestinal digestion and fermentation in the large intestine. Here I outline that the method is utterly flawed and conclude that it is unsuitable for making claims as to the availability, fermentability, and food energy value of carbohydrates. More traditional methods, although more demanding of time and effort, can be used. Otherwise further development of methodology is essential to avoid undue risk of bias.
Keywords: Carbohydrate; breath hydrogen; caloric value; dietary fiber; methodology.