DASH Diet Leads to Decreased Gestational Weight Gain

A randomized clinical trial in obese or overweight pregnant women evaluating the use of a modified diet regimen shows a beneficial effect of a modified Dietary Approach to Stop Hypertension (DASH) diet on gestation weight gain (GWG) compared with usual care.

Obesity in US women at reproductive age is very common and leads to increased GWG. Children born from obese mothers have an estimated risk of greater than 50% of being overweight themselves. Updated GWG guidelines from 2009 state of a goal of 7.0 to 11.5 kg for overweight women (BMI 25-30) and 5.0 to 9.1 kg for obese women (BMI >30).

It is common knowledge that a limitation in calories will help reduce weight, but also that prenatal women should maintain a healthy energy and nutritional intake. Thus, for the overweight population, a difference in diet may help decrease GWG. To help maintain guideline recommendations, a randomized controlled trial by Horn et al sought to determine if a DASH-type diet would limit GWG.

“We need to help these women, who make up the majority of pregnancies in the U.S, leverage this unique opportunity during their pregnancy to adopt a healthier diet and lifestyle plan that they can follow throughout pregnancy and, hopefully, post-partum,” said lead author Linda Van Horn, PhD, RD, professor of preventive medicine at Northwestern University Feinberg School of Medicine, in a statement. “These results show promise in harnessing modern technology to help a mom achieve those goals.”

From 2012 to 2015, eligible obese or overweight pregnant women at gestation age <16 weeks were randomized to either receive a modified DASH-type diet (Mama-DASH) and lifestyle interventions or just usual care. The modified DASH diet included fish, skinless poultry, lean meat and vegetable proteins, whole grains, fruits, vegetables, legumes, and unsaturated fats. Avoidance of fish high in mercury and an increase in calcium-rich foods created a diet more suitable for the childbearing population. Patients in the DASH-type diet group also received a pedometer and were encouraged to have at least 30 minutes of activity or walk 10,000 steps a day. They were also encouraged to sleep between 7 to 9 hours daily.

At 35 weeks, the DASH-type diet group had a GWG of 10 kg while the usual care group had a GWG of 12 kg (P = .02). Most patients in both groups had GWG that exceeded GWG guidelines, but significantly less in the DASH-diet group (69% vs 85%, P = .004). Secondary outcomes such as blood pressure, gestational age at delivery, gestational diabetes, infant birth weight, and percentage of body weight, did not vary significantly between the 2 groups. Interestingly, cesarean section deliveries were more common among the DASH-diet group, exclusively with obese pregnant women (40% vs 27%, P = .03).

Aside from the increased cesarean section deliveries, patients in the DASH-diet group had significantly improved GWG compared with patients who only received usual care. Most importantly the lower GWG obtained from the modified DASH-diet did not lead to an increase in adverse events for the mother or the newborn. Diet seems to be an important factor to consider for pregnant women, and a healthy diet will lead to better nutrition quality.

“MOMFIT demonstrates the feasibility of counseling pregnant women in healthy diet and lifestyle behaviors through nutrition coaching using modern technology,” Van Horn said. She believes that this model could be effectively utilized in a clinical setting to help pregnant women achieve recommended weight-gain goals.

Reference

Horn VL, Peaceman A, Kwasny M, et al. Dietary approaches to stop hypertension diet and activity to limit gestational weight: maternal offspring metabolics family intervention trial, a technology enhanced randomized trial. Am J Prev Med. 2018;55(5):603-614. doi: 10.1016/j.amepre.2018.06.015.