Yale Research Shows Leptin Spurs Body To Shift From Burning Carbs To Fat

The Yale study, led by Gerald I. Shulman, professor of medicine and cellular & molecular physiology, examined the rate of fat and carbohydrate metabolism in rats during starvation as they transitioned from a fed to a fasting state. The research team’s analyses yielded new insights about leptin biology. During starvation, Shulman said, plasma leptin levels fall, activating a pathway that promotes the breakdown of fat and mediates this critical shift from glucose to fat metabolism. While a drop in insulin also occurs, a decrease in leptin is also necessary for this process to happen, the researchers discovered. “We found a new role for leptin in terms of energy maintenance, and the maintenance of nutrient supply to the brain during starvation,” Shulman said. “This leptin-mediated glucose-fatty acid cycle may be evolutionarily important for survival during times of famine.” Reference: “Leptin Mediates a Glucose-Fatty Acid Cycle to Maintain Glucose Homeostasis in Starvation” by Rachel J. Perry, Yongliang Wang, Gary W. Cline, Aviva Rabin-Court, Joongyu D. Song, Sylvie Dufour, Xian Man Zhang, Kitt Falk Petersen and Gerald I. Shulman, 4 January 2018, Cell.DOI: 10.1016/j.cell.2017.12.001