The effect of three dietary regimes on the amount of Schiff base adducts, as well as acid-stable (Amadori) glycation adducts in murine hepatic cytosolic fractions was studied. The dietary regimes consisted of an unrestricted diet or two different diets in which the caloric restriction was 25 and 50% of the caloric intake of unrestricted animals. The concentration of the Schiff bases in ad libitum and slightly restricted mice (25%) was higher than that observed in severely restricted mice (50%). The concentration of the Schiff bases in the severely restricted mice did not reach values observed in ad libitum or slightly restricted mice even in 45-month old animals. The concentration of the Amadori products was essentially the same for all three dietary groups. Our results show that a severe caloric restriction decreases the formation of early glycation adducts which might influence the rate of aging of laboratory animals under caloric restriction.