High dietary fiber and low saturated fat intake among oligomenorrheic undergraduates. Numerous functional risk factors are associated with the occurrence of secondary amenorrhea in young women. Less is known regarding factors associated with the more prevalent problem of oligomenorrhea. We have evaluated nutrient intake, body composition, perceived psychological stress, 24-hour urinary cortisol, and urinary C peptide (UCP) in 35 eumenorrheic, 11 mildly oligomenorrheic, and 10 oligomenorrheic nonathletic undergraduate women. Nutrient intake was evaluated by a validated food frequency questionnaire. Oligomenorrheic women were found to consume significantly more dietary fiber, crude fiber, and polyunsaturated fat, and significantly less saturated fat than their eumenorrheic classmates. Oligomenorrheic women had significantly lower 24-hour UCP excretion than mildly oligomenorrheic women. The groups did not differ in any aspect of body composition, body weight, age of menarche, perceived psychological stress, or urinary cortisol excretion. The data suggest that higher intake of fiber and lower intake of saturated fat may be associated with oligomenorrhea among otherwise healthy undergraduate nonathletic women. 