Marc Lobliner and Kara Corey discuss RD Nutrition Fitburn. RD Nutrition FitBurn is formulated to provide scientifically-validated doses of proven ingredients to help with Appetite Control, Weight Management, Cortisol Balance and Thyroid Support. FitBurn supports Healthy Insulin Resistance, Glucose Metabolism, Heart Health and Immune System Health. By addressing multiple factors involved in fat loss, FitBurn is the fat loss formula that can help you reach your goals. Designed by Registered Dietitian Kara Corey for maximum results.