A Randomized Controlled Trial Investigating the Effects of a Low–Glycemic Index Diet on Pregnancy Outcomes in Gestational

OBJECTIVEdThe prevalence of gestational diabetes mellitus (GDM) is rising. There is little evidence to demonstrate the effectiveness of one dietary therapy over another. We aimed to investigate the effect of a low–glycemic index (LGI) versus a conventional high-fiber diet on pregnancy outcomes, neonatal anthropometry, and maternal metabolic profile in GDM. RESEARCHDESIGNANDMETHODSdNinety-nine women (age 26–42 years; mean6 SD prepregnancy BMI 24 6 5 kg/m2) diagnosed with GDM at 20–32 weeks ’ gestation were randomized to follow either an LGI (n = 50; target glycemic index [GI] ~50) or a high-fiber moderate-GI diet (HF) (n = 49; target GI ~60). Dietary intake was assessed by 3-day food records. Pregnancy outcomes were collected from medical records. RESULTSdThe LGI group achieved a modestly lower GI than the HF group (mean 6 SEM 476 1 vs. 536 1; P, 0.001). At birth, there was no significant difference in birth weight (LGI 3.36 0.1 kg vs. HF 3.36 0.1 kg; P = 0.619), birth weight centile (LGI 52.56 4.3 vs. HF 52.26 4.0; P = 0.969), prevalence of macrosomia (LGI 2.1 % vs. HF 6.7%; P = 0.157), insulin treatment (LGI 53 % vs. HF 65%; P = 0.251), or adverse pregnancy outcomes. CONCLUSIONSdIn intensively monitored women with GDM, an LGI diet and a conven-tional HF diet produce similar pregnancy outcomes. Diabetes Care 34:2341–2346, 2011 Gestational diabetes mellitus (GDM)is commonly defined as any degreeof glucose intolerance with onset or first recognition during pregnancy (1). In developed nations, between 4 and 8 % of pregnant women are presently affected (2–4), and the prevalence will rise dra-matically if the guidelines of the new In