Gestational diabetes is diabetes that occurs during pregnancy in women who were not previously diabetic. If left uncontrolled, it can have adverse effects on the developing foetus. Its treatment depends on the severity of the condition, with diet, oral medication and insulin being the three mainstay options. Insulin therapy is generally seen as the last line of defence in treating gestational diabetes.
One of the dietary approaches that has been touted for diabetes is a low glycaemic index (GI) diet. This is a diet that emphasises carbohydrate sources that release their sugar relatively slowly into the bloodstream. Overall, these diets do seem to benefit biochemical parameters in diabetes, which is no surprise seeing as the fundamental problem in diabetes is disordered blood sugar control.
In a recent study, a low GI diet was pitted against a high GI one in gestational diabetes. 31 women were randomised to eat the low GI diet, and of these 9 (29 per cent) needed to use insulin to control their condition. On the other hand, of the 32 women eating a higher GI diet, 19 (59 per cent) required insulin. These results were statistically significant. Or to put it another way, in this study, a low GI diet (compared to a high GI diet) reduces the risk of needing insulin by half.
In this study, those on a high GI diet requiring insulin were switched to a low GI one. 9 of these 19 women who required insulin were able to avoid insulin through this switch.
A low GI diet may contain meat, fish, eggs, nuts, seeds, vegetables other than the potato, certain fruits (e.g. apples, berries), bean and lentils. Of course, adopting such a diet prior to pregnancy may well reduce the risk of developing gestational diabetes in the first place. And eating such a diet after pregnancy may well reduce the risk of developing full-blown diabetes later on too.
Moses RG, et al. Can a low-glycemic diet reduce the need for insulin in gestational diabetes mellitus? A randomized trial. Diabetes Care 2009;32:996-1000