Study is an interventional clinical trial. Pregnant women (aged 25-40 years) diagnosed with GDM (by a 75-g oral glucose tolerance test at 24-28 weeks' gestation) will be recruited conveniently from Obstetrics and Gynecology clinic at the Jordan University Hospital and National Center for Diabetes, Endocrinology and Genetics, Amman, Jordan. A sample of 180 pregnant women with GDM (60 women who do not use insulin and hypoglycemia medications, 60 women who are treated with metformin, 60 women who are treated with insulin), who will meet the inclusion criteria and will be agreed to participate will be centrally randomized to follow carbohydrate counting dietary intervention, carbohydrate counting and DASH dietary intervention, and control dietary intervention.