Low-fat/calorie products were originally developed for diabetics and people with specific health problems and they were considerably expensive. Nowadays, consumers' demand for low-fat/calorie products has significantly raised in an attempt to limit health problems, to lose or stabilize their weight, and to work within the frame of a healthier diet. The food industry has been confronted with a new challenge in order to satisfy consumers; development of low-fat/calories products with acceptable sensory characteristics and competitive price, by preferably employing the conventional processing equipment and in agreement with current strict legislation. The role of fat replacers and sugar substitutes in the successful manufacture of these products is crucial.