In the United States, 5–9% of pregnant women develop gestational diabetes mellitus (GDM) according to the US Centers for Disease Control and Prevention (2024a, b). While treatment exists, prevention should be prioritized, as GDM diagnosis leads to several complications in the mother and infant. Fetal macrosomia risk is 15–45% in pregnant women with GDM, and fetal macrosomia increases the risk of peritoneal trauma in the mother during childbirth, as well as metabolic complications in the newborn in later years. Evidence-based medical nutrition therapy (MNT) plays a key role in the prevention and management of GDM. Plant-based diets have been proven to decrease the risk of developing GDM as well as in its management and complications. The Mediterranean (MED) diet is an evidence-based dietary pattern that aids in prevention of disease progression of T2DM, making it a dietary tool for GDM control. The dietary approach to stop hypertension (DASH) diet is another plant-based diet that supports the management of T2DM and cardiovascular disease, as it was originally created for the management of blood pressure. GDM can also be managed with individual plant-based food groups such as vegetables, fruits, nuts, seeds, oats, and whole grains. Research on the usage of dietary supplements also supports their ability to manage diabetes including GDM.