Recent years have witnessed an increase in the prevalence of maternal obesity during pregnancy in the United States and worldwide. Obese women have increased risks for gestational problems, such as diabetes, hypertension, and pre-eclampsia. Further, gestational obesity can adversely impact fetal growth and result in macrosomia, congenital abnormalities, and even fetal death. Measures must be taken to reduce maternal adiposity, as even a modest weight loss during pregnancy is beneficial for the health of mothers and fetus. Calorie restriction and moderate exercise are proven safe methods of stopping weight gain and/or inducing white-fat loss in these subjects. Additionally, therapeutic drugs that activate the AMP-activated protein kinase signaling pathway may be effective in ameliorating pathological conditions in obese patients. Finally, dietary supplementation with L-arginine or its effective precursor (L-citrulline) may be beneficial for managing overweight or obese gestating women by reducing white-fat accretion. Because of ethical concerns over human studies, animal models (e.g., sheep, pigs, baboons, rats, and mice) are warranted to test novel hypotheses with enormous biological significance and clinical applications.