Measuring the effect of a healthy diet

The women were given three scores to reflect the similarity of their eating habits to three different dietary patterns. All three diets encouraged high intakes of fruits, vegetables, nuts, and legumes. In addition:

• Mediterranean diet scores increased with higher amounts of whole grains and fish, moderate intake of alcohol, and low consumption of red meat and saturated fats;
• DASH scores increased with higher amounts of whole grains and low-fat dairy foods, and low intakes of red meat, sugary beverages, and sodium (salt);
• and, Healthy Eating Index scores were higher in women who consumed greater amounts of cereal grains and moderate amounts of alcohol, had more white than red meat, took a daily multivitamin, and limited their intake of trans and saturated fats.

Healthy eating habits predict a healthy pregnancy

The study found that:

• Women who stuck closely to any of the healthy diets were less likely to develop gestational diabetes.
• Compared with low-scoring women, women with the highest Mediterranean diet scores reduced their risk by 24%, those with the highest DASH scores reduced their risk by 34%, and those with the highest Healthy Eating Index scores reduced their risk by 46%.
• The Healthy Eating Index eating pattern was significantly more powerful at protecting against gestational diabetes than either of the other two eating patterns.
• It appeared that none of the individual dietary components were responsible for the protective effects. This suggests that all of the aspects of a healthy eating pattern work together to protect women.

"All three dietary patterns were significantly associated with a reduced risk of gestational diabetes mellitus, suggesting a potentially robust role of a variety of dietary factors in the development of gestational diabetes mellitus," the study's authors said.

Eat well before pregnancy

• Maintain a healthy weight. Women who are overweight prior to pregnancy are at higher risk of developing gestational diabetes as well as other dangerous pregnancy complications.
• Exercise regularly. Staying fit before and during pregnancy helps keep blood sugar levels stable and prevent pregnancy complications including gestational diabetes.
• Remember the components of a healthy diet. That is, fruits, vegetables, whole grains, nuts, seeds, and legumes.
• Consider a multivitamin. Regular multivitamin use may have contributed to the more powerful effect of the Healthy Eating Index dietary pattern.

(Am J Clin Nutr 2012;96:289-95)