Discussion
We found that US women who bore at least 1 live infant during the previous 10 years had, on average, poor diet quality and that overall diet quality was worse among women with a history of GDM. Women with a history of GDM have a markedly elevated risk for developing type 2 diabetes compared with women without GDM. To prevent type 2 diabetes, the American College of Obstetrics and Gynecology and American Diabetes Association recommend that all women at increased risk for the disease be counseled about the benefits of a healthy and balanced diet, exercise, and weight management. Our findings highlight the need for public health and clinical attention on diet quality among childbearing women, particularly those with a history of GDM.
Women reported suboptimal consumption of most diet-quality components, with mean scores close to 50% of the maximum score. Average consumption of greens and beans and whole grains was particularly low, with scores approximately 15% to 20% of the maximum. Women with a history of GDM had significantly lower consumption of greens and beans compared with women without a history of GDM. These foods may be of particular benefit for reducing type 2 diabetes risk, and their consumption should be encouraged among childbearing women, particularly those with a history of GDM. One recent systematic review and meta-analysis showed that greater consumption of green leafy vegetables was associated with a 14% reduction in the risk of type 2 diabetes. Beans and peas are great sources of protein, fiber, and many vitamins and minerals. One review suggested that replacing high energy-dense food with beans and peas would have beneficial effects on the prevention and management of obesity and other comorbidities. Consumption of beans could also improve overall diet quality. Women with a history of GDM should be counseled to include more greens and beans to improve their diet quality and meet dietary recommendations to reduce the risk of type 2 diabetes.
In addition to links with increased chronic disease risk for women, maternal diet quality is a significant contributor to children's diet quality, and women who modify their diet typically make comparable changes to their children's diet. In a study of women with children at home, women with a history of GDM were less likely to meet the national guidelines for fruit and vegetable consumption. Improving diet quality among childbearing women, especially those with a history of GDM, has the potential for positive intergenerational health effects.
Our study has several strengths and limitations. The use of data from a large national health study enabled us to generalize our results to the 19 million noninstitutionalized US women aged 20 to 44 years who gave birth to at least 1 live infant within the previous 10 years. Two 24-hour interviewer-administered dietary recalls produce a better estimate of women's usual dietary intake than a single recall. We assessed diet quality by using the HEI-2010, which is a valid and reliable measure of diet quality in NHANES. We used individual food and nutrient data to generate the HEI-2010 diet quality score, which allowed for detailed analysis of overall and individual components of diet quality. Although misclassification is possible, a self-reported history of GDM has a high level of agreement with GDM data gathered from birth certificates. Women self-reported their age only at first GDM diagnosis; therefore, we have no knowledge of whether they also had GDM during their most recent pregnancies. NHANES is a cross-sectional survey, and thus, we did not have information on diet quality before pregnancy, during pregnancy, or any time after their most recent pregnancies.
Childbearing women in the United States have, on average, poor diet quality. Women with a history of GDM have significantly lower overall diet quality and reported lower consumption of greens and beans than women without a history of GDM. Given the role of diet quality in the prevention of type 2 diabetes and other chronic diseases, our findings highlight the need for, and importance of, public health and individual clinical interventions to increase consumption of total protein, greens and beans, and whole grains to improve the overall diet quality of women of childbearing age, particularly women with a history of GDM.