Relationships between dietary nutrients and plasma and fecal estrone, estradiol-17 beta, testosterone, and plasma prolactin concentrations were studied in young Seventh-day Adventist men: 18 nonvegetarians (NVs), 20 lactoovovegetarians (LOVs), and 15 vegans (V). Blood samples and 3-d dietary records were obtained. Contemporaneously collected diet composites and stool samples were analyzed for fiber. Vs and LOVs consumed significantly more fiber than did the omnivores, whereas NVs and LOVs consumed more saturated fatty acids than did Vs. Although plasma steroid-hormone status did not differ, Vs had significantly higher fecal estrogen concentrations than did NVs or LOVs. Plasma prolactin concentrations were significantly higher in NVs and LOVs than in Vs. Significant relationships were observed for the combined groups between dietary and fecal fiber components and fecal, but not plasma, steroid hormones. For the combined groups, prolactin concentrations were positively correlated with saturated fatty acid intake. Further research on the effects of dietary nutrients on endocrine homeostasis in other age groups is warranted.