Short-term effect of plant-based Nordic diet versus carbohydrate-restricted diet on glucose levels in gestational diabetes – the eMOM pilot study

Abstract

Abstract Background The optimal nutritional treatment for gestational diabetes (GDM) is still a matter of debate. With increasing rates of GDM and potential negative consequences for the health of mother and child, the best treatment should be established. The Nordic diet with emphasis on plant-based protein shows promising health outcomes in other populations but has yet to be investigated in GDM population. The aim of the eMOM pilot study was to compare the short-term effects of healthy Nordic diet (HND) and the currently recommended moderate restriction of carbohydrates diet (MCRD) on glucose and lipid metabolism in women with GDM. Methods This was a 14-day randomized crossover diet intervention. In total, 42 pregnant women diagnosed with GDM (< 29 + 0 gestational week) were randomized. The run-in to the crossover was three days of the participants’ regular diet, followed by the first allocated three-day intervention diet. This was followed by the second three-day intervention diet. The intervention diets were separated by a three-day wash-out period consisting of the participants’ regular diet. All participants wore a continuous glucose monitor (CGM, Freestyle Libre®, Abbott, USA) for 14 days, and gave blood samples four times during the crossover. The primary outcome was time spent in glucose target range (TIR, < 7.8 mmol/L). TIR, 3-day mean tissue glucose as well as changes in fasting glucose, homeostatic model of insulin resistance (HOMA-IR) and blood lipids were analyzed with paired samples statistical analyses. Results 36 women with complete 14 days CGM data were analyzed. Both diet interventions produced a high degree of TIR (98% SD 1.8), without a difference between the diets (p = 0.727). The 3-day mean glucose was significantly lower in HND than in MCRD (p = 0.049). Fasting insulin (p = 0.034), insulin resistance (p = 0.03), total and LDL cholesterol (p = 0.023 and 0.008) reduced more in the MCRD diet than the HND. NS differences in any other measure of CGM or blood tests. Conclusions HND and MCRD did not differ in terms of their short-term effect on TIR. A larger study with sufficient power is needed to confirm the differences in short-term mean glucose, insulin resistance and lipid metabolism. Trial registration: Registered in clinicaltrials.gov (21/09/2018, NCT03681054).