We developed hard biscuit containing 30% wheat bran (WB biscuit) and administered it to 12 volunteers at 7.5 g/day (7.5 g group) or 15 g/day (15 g group) as wheat bran for 12 weeks. After 12 weeks, the dietary fiber intake from foods other than wheat bran decreased slightly in the both groups, in the 15 g group was the decrease notable especially, after the beginning of WB biscuit administration. We suggest that a closest attention to changes in dietary habit associated with intervention is needed in intervention studies using patients leading a normal life.