Eight healthy subjects (average age 27. 5 years old) were orally administered 200 ml of the control solution (containing 50 g of glucose) or the test solutions (containing 50 g of glucose and 5 g of glucomannan or cellulose), and compared with the suppressive effect on the enhancement of blood glucose level. Glucomannan delayed the intestinal absorption of glucose and could significantly suppress the maximal level of blood glucose, but cellulose could not. Addition of pullulan of 5 or 10 g to glucose solution also did not show the suppressive effect on blood glucose level.