GDM is characterized by many metabolic changes diverting physiology to pathophysiology. Although the main focus over the years was on research of carbohydrate metabolism, significant changes ensue in lipid and protein metabolism as well. GDM has been considered an entity for >30 years, but no consensus exists concerning the metabolic goals in managing it or for its diagnosis. General agreement exists that treatment should be aimed to restore normality. However, until recently, only scarce data existed concerning normal glycemic profiles in nondiabetic pregnancies, and treatment goals were settled by different academic societies without the support of evidence-based data. Importantly, as presented in this review, enhanced pregnancy outcome in GDM can be achieved with glycemic thresholds that are higher than found in normal pregnancy. Yet, randomized prospective studies are needed to support the hypothesis that achievement of even tighter glycemic targets will enhance pregnancy outcome in GDM. Although the metabolic changes in protein and lipid metabolism in GDM in comparison to normal pregnancies is apparent, scarce information exists regarding this issue. It is not clear whether monitoring these changes during diabetic pregnancy and attempting to mimic normality will enhance pregnancy outcome in GDM subjects. Prospective studies are needed to clarify this issue.