The glycaemic index (GI) is reviewed as example of chronological parameters of carbohydrate utilisation. A food utilisation depends not only on nutrient composition and physical properties of food but also on body metabolism and physiological status including individual peculiarities, daily rhythm and other chronological characteristics of body connected with energy metabolism and biosynthesis of glycoproteins, phospholipids and nucleic acids. Such analytical approaches are very important for practice of human nutrition and animal feeding and also for critical analysis of "fashion" theories in nutrition.