Effect of a low glycaemic index diet on blood glucose in women with gestational hyperglycaemia

Aim: 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. Methods: 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. Results: 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. Conclusions: 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. (C) 2010 Published by Elsevier Ireland Ltd.