How often you have to urinate depends on how much fluid you drink and the level of stimulatory signals sent to your bladder. One substance that may make you have to urinate more often is caffeine, though caffeine's effect on urinary output diminishes with regular use. If you feel like you are urinating too frequently, however, removing caffeinated beverages from your diet may be helpful in reducing frequency.
A Limited Diuretic Effect
Caffeine has long been considered a diuretic, which means that it increases the amount of urine produced. This reputation may not be completely accurate, however. "The New York Times" reports that drinking a caffeinated beverage increases urinary output only as much as water. An article in a 2003 issue of the "Journal of Human Nutrition and Diet" explained that consuming 250 to 300 milligrams of caffeine (equivalent to two to three cups of coffee) can cause a mild increase in urine in people who have not had any caffeine for several days. The body, however, quickly becomes tolerant to the effects of caffeine, which minimizes the stimulant's diuretic effect.