Effect of a low glycaemic index diet on blood glucose in women with gestational hyperglycaemia. A randomized controlled trial investigating the effects of a low-glycemic index diet on pregnancy outcomes in gestational diabetes mellitus.
The objectives of this pilot study were to determine the feasibility and effect on glycaemic control of a low-glycaemic-index (GI) diet in women with gestational diabetes or impaired glucose tolerance of pregnancy.
                participants, recruited from the Diabetes-in-Pregnancy Clinic of an inner-city teaching hospital serving a predominantly non-Caucasian population, were randomized to a low-GI (n=23) or control (n=24) diet and followed from 28 weeks gestation until delivery. Self-monitored-blood-glucose (SMBG), maternal and infant weight were collected from medical charts. Dietary intakes were assessed using diet records and questionnaires.
                diet GI on control (58, 95% CI: 56,60) was significantly higher than on low-GI (49, 95% CI: 47,51; p=0.001). Glycaemic control improved on both diets, but more postprandial glucose values were within target on low-GI (58.4% of n=1891) than control (48.7% of n=1834; p<0.001). SMBG post-breakfast was directly related to pre-pregnancy BMI in the control, but not the low-GI group (BMI*diet interaction; p=0.021). Participants accepted the study foods and were willing to consume them post-intervention.
                a low-GI diet was feasible and acceptable in this sample and facilitated control of postprandial glucose. A larger study is needed to determine the effect of a low-GI diet on maternal and infant outcomes.
                2010. Published by Elsevier Ireland Ltd. The 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.
                Ninety-nine women (age 26-42 years; mean ± SD prepregnancy BMI 24 ± 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.
                The LGI group achieved a modestly lower GI than the HF group (mean ± SEM 47 ± 1 vs. 53 ± 1; P < 0.001). At birth, there was no significant difference in birth weight (LGI 3.3 ± 0.1 kg vs. HF 3.3 ± 0.1 kg; P = 0.619), birth weight centile (LGI 52.5 ± 4.3 vs. HF 52.2 ± 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.
                In intensively monitored women with GDM, an LGI diet and a conventional HF diet produce similar pregnancy outcomes.
While a low glycaemic index diet was seen to be beneficial for some outcomes for both mother and child, results from the review were inconclusive. Further trials with large sample sizes and longer follow up are required to make more definitive conclusions. No conclusions could be drawn from the high-fibre versus control-diet comparison since the trial involved did not report on many of the outcomes we prespecified.