Eating a healthy, calorie-controlled diet during pregnancy can help prevent excessive weight gain and cut the risk of obstetric complications, researchers report. In Europe and the United States, up to 40 percent of women gain more than the recommended weight during pregnancy and this excess weight is associated with a number of major health problems, according to background information in the study published online May 17 in the BMJ. In the report, an international team of researchers reviewed the findings of 44 studies that included more than 7,200 women and found that dietary intervention resulted in an average reduction in weight gain during pregnancy of nearly 8.8 pounds, compared with 1.5 pounds for exercise, and 2.2 pounds for exercise and diet combined. Dietary intervention alone also provided the most benefit in preventing serious pregnancy complications such as preeclampsia (a sudden spike in the mother's blood pressure after the 20th week of pregnancy), diabetes and premature birth, according to lead researcher Dr. Shakila Thangaratinam from Queen Mary, University of London, and colleagues. The study authors concluded that dietary and lifestyle interventions in pregnancy improve outcomes for both mother and baby. However, an accompanying editorial suggested that there is not enough evidence to support dietary or any other type of intervention.