The aim of diabetes management is to normalise blood glucose levels since improved blood glucose control is associated with fewer complications. Food affects blood glucose levels; however, there is no universal approach to the optimal diabetic diet and there is controversy about the usefulness of the low-glycaemic index (GI) diet. To assess the effects of low-GI diets on glycaemic control in diabetes, we conducted electronic searches of the Cochrane Library, MEDLINE, EMBASE and CINAHL. We assessed randomised controlled trials (RCT) with interventions >4 weeks that compared a low-GI diet with a higher-GI diet for type 1 or type 2 diabetes. Twelve RCT (n 612) were identified. There was a significant decrease in glycated Hb (HbA1c) with low-GI diet than with the control diet, indicating improved glycaemic control (seven trials, n 457, weighted mean difference (WMD) − 0·4 % HbA1c, 95 % CI − 0·7, − 0·20, P = 0·001). In four studies reporting the results for glycaemic control as fructosamine, three of which were 6 weeks or less in duration, pooled data showed a decrease in fructosamine (WMD − 0·23 mmol/l, 95 % CI − 0·47, 0·00, P = 0·05), n 141, with low-GI diet than with high-GI diet. Glycosylated albumin levels decreased significantly with low-GI diet, but not with high-GI diet, in one study that reported this outcome. Lowering the GI of the diet may contribute to improved glycaemic control in diabetes.
(Received June 19 2009)
(Revised March 22 2010)
(Accepted March 24 2010)
(Online publication April 27 2010)
Abbreviations: CHO, carbohydrate; GI, glycaemic index; GSA, glycated serum albumin; HbA1c, glycated Hb; RCT, randomised controlled trial