Glycemic control in women with GDM: Insights from a randomized controlled pilot trial on plant-based Nordic Healthy diet versus moderately carbohydrate restricted diet

Abstract Background: Gestational Diabetes Mellitus (GDM) prevalence is rising worldwide. GDM poses health risks for both mothers and offspring. Optimal dietary strategies for GDM remain unclear. The eMOM pilot compared a plant-protein rich Healthy Nordic Diet (HND) and a moderately carbohydrate restricted diet (MCRD) and their potential effects on glucose control and newborn body composition. Methods: Forty-two (HND, n = 20, MCRD, n = 22) participants were assigned to have dietary intervention and nutritional counseling from gestational weeks (GW) 24 + 0–28 + 6 (baseline) until delivery. Continuous glucose monitoring (Freestyle Libre, Abbott, USA) assessed glucose levels. Blood samples for glucose and lipid metabolism and 3-day food diaries were collected at baseline and at GW 34 + 0–35 + 6. Neonatal body composition was measured (Peapod, COSMED, USA). Difference between groups and newborn body composition was analysed with t-test and Wilcoxon test. Results: Thirty-two women completed the study. Both groups maintained the glucose time in range (≤ 7.8 mmol/L) during majority of the time (98.9 and 99.3% for MCRD and HND respectively, p = 0.921) in GW 34 + 0–35 + 6. The mean glucose was lower in the MCRD group compared to the HND group (5.0 SD 1.03 vs. 5.2 SD 0.96 mmol/l, p < 0.001). No differences were observed between the groups in glucose variability, lipid metabolism, gestational weight gain, or in the body composition of the newborns. There was no difference in the macronutrient composition between the groups as the HND had lower macronutrient adherence than the MCRD. The HND decreased intake of meat and increased fish consumption significantly compared to the MCRD. Conclusions: This pilot study indicates that both a moderately restricted carbohydrate diet and a diet focused on plant-based protein effectively maintained a large time within the treatment target range in women with GDM. Further research could explore the impact of protein quantity and sources in maternal diets on glycemic control and newborn outcomes. Trial registration The eMOM pilot trial is registered in Clinicaltrials.gov (21/09/2018, NCT03681054)