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

Abstract

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.