Arguments over recommended carbohydrate intake have a long history and it doesn’t appear to be close to ending any time soon. Typical mainstream recommendations have carbohydrates contributing 50% or more of total calories while many low-carbohydrate advocates suggest far fewer (ranging from the 40% of the Zone diet to close to zero for ketogenic diets).
In theory, you can make arguments for or against any of these approaches in terms of superiority. In the real world, it’s not quite that simple. You can always find folks (and this is true whether they are bodybuilders or just general dieters) who either succeeded staggeringly well or failed miserably on one or another approaches.
In this chapter, I want to give readers a very brief and simplified overview of human metabolism and nutrient use. Which, for those who know a lot about the topic will realize, is an understatement of vast proportion. The complexities of human metabolism can and do fill up hundreds of pages in physiology books and this chapter should be taken with that in mind.