Dietary Management of Gestational Diabetes Mellitus

The goal of this clinical trial is to test effect of dietary management program based on the nudge strategy in gestational diabetes mellitus patients. The main questions it aims to answer is whether the dietary management program is effective for the diet management behavior of gestational diabetes mellitus patients. Participants will receive a 12 week dietary management program. The intervention group will receive a diet management program based on the nudge strategy, and the control group will receive a routine dietary management program. Researchers will compare two group's glycemic control and pregnancy outcomes and to see if effective for the diet management behavior.