Low glycemic diet may improve pregnancy outcome

NEW YORK (Reuters Health) - Moms-to-be who eat a low glycemic index diet may have healthier babies, a study from Australia suggests.

The glycemic index of a food is the measure of how quickly blood sugar (glucose) rises after meals. In general, low-fiber foods containing simple starches, for example candy, have a higher glycemic index than foods rich in fiber and more complex carbohydrates, such as whole wheat bread and vegetables.

The effect of dietary glycemic index on weight and chronic disease is still controversial, Dr. Robert G. Moses of Wollongong Hospital in New South Wales and colleagues note. But given that maternal glucose is the main source of nutrition for fetal growth, they add, the glycemic index of a pregnant woman's diet could be expected to play a role in fetal health.

To investigate, Moses and his team instructed 62 pregnant women to either eat plenty of low-glycemic index foods or stick to high-fiber foods with a moderate-to-high glycemic index. Women said they had an easier time following the low-glycemic index diet.

Infants born to the 30 women on the high-glycemic index diet were heavier than the babies of the 32 women on the low- glycemic index diet. These infants also had a higher ponderal index, a measure of weight in relation to length. One third of the babies whose mothers were on the high-glycemic index diet were heavy for their gestational age, compared to 3.1 percent of the infants whose mothers ate a low-glycemic index diet.

While the study wasn't designed to investigate whether dietary glycemic index influences the risk of gestational diabetes, Moses and his colleagues note, the findings suggest this is possible.

"Because birth weight and ponderal index predict long-term risk of obesity and chronic disease, a low- glycemic index diet in pregnancy may favorably influence long-term outcomes," the researchers write. They conclude by calling for larger studies to investigate the effect of a low-glycemic index diet on gestational diabetes risk.

SOURCE: American Journal of Clinical Nutrition, October 2006.