A randomized clinical trial of a fiber-enriched diabetic diet vs. the standard American Diabetes Association-recommended diet in the management of diabetes mellitus in pregnancy

Objective: In light of the reported effectiveness of high-fiber diets in achieving improved glycemic control and reducing insulin requirements in the nonpregnant diabetic state, along with the need to maintain euglycemia in pregnancy, we initiated a randomized trial to test the effects of a high-fiber diet on metabolic control and pregnancy outcomes. Methods: Subjects were assigned to either the American Diabetes Association (ADA) diet or a fiber-enriched diet (80 g/day; 40 g/day of fiber in fiber-rich foods and an additional 40 g/day in a high-fiber drink). Of the 50 subjects randomized (24 to fiber-enriched diet and 26 to ADA diet), 28 were insulin-dependent diabetics (13 to fiber-enriched diet and 15 to ADA diet) and 22 were gestational diabetics (11 to fiber-enriched diet and 11 to ADA diet). Results: Dietary compliance was good in 60% and acceptable in 40%; in none was compliance considered unacceptable. The number of hypoglycemic episodes was lower in the fiber-enriched diet group than in the ADA diet subjects; however, no significant difference was observed between the two treatment groups regarding the overall glycemic control (mean blood glucose and mean glycosylated hemoglobin levels), the mean number of hypoglycemic reactions, the mean birth weight, and the mean gestational age at delivery. Conclusion: A fiber-enriched diet did not improve overall glycemic control in our study group. However, fewer hypoglycemic episodes were associated with this diet therapy. Further studies are needed to explore the role of fiber therapy during pregnancy in reducing aberrant glycemic excursions.