With the unending variety of diet systems out there many fitness-conscious or athletically-driven people have difficulty choosing which strategy to follow. This basic information will help your assess any diet program.

From http://www.ketogenic-diet-resource.com, the following chart shows exactly why we do not require carbohydrates at all. If you want to learn how the metabolism operates in fed, fasted and starvation situations, this resource will provide you with some great information:

Metabolic Pathways: How the Body Uses Energy

Metabolic pathways in the body determine how we utilize the macronutrients (carbohydrates, proteins and fats) we eat, and ultimately what happens to the fuels that come from each macronutrient.  It all depends on when the last meal was finished.  If the body is in a "fasting or starvation" mode, energy pathways will behave differently than when food is available.

From ketogrenic-diet-resources.com

A basic understanding about these processes will help you in making your nutritional choices. For more info, go to http://www.ketogenic-diet-resource.com/metabolic-pathways.html