In starvation times, researchers say, animals were more likely to survive if they could hoard and stretch out their stored energy. Even if an animal secured a rare feast, evolution smiled on the storage of excess fuel as fat, given the likelihood of a quick return to starvation.
“We discovered an anti-starvation mechanism that has become a curse in times of plenty because it sees cellular stress created by overeating as similar to stress created by starvation — and puts the brakes on our ability to burn fat,” says lead study author Ann Marie Schmidt, MD, the Dr. Iven Young Professor of Endocrinology at NYU School of Medicine.
Published online July 16 in Cell Reports, the current study reveals that the natural function of a protein called RAGE on the surface of fat cells is to stop the breakdown of stored fat in the face of stress. Its existence may partly explain why 70 percent of American adults are overweight or obese, according to the American Heart Association (AHA). In March 2017, the AHA announced a grant to help researchers find the elusive “metabolic brake.”
The AHA funding followed a 2016 study that found contestants from America’s Greatest Loser gained back their lost pounds after the show ended. Why did their metabolisms slam to a halt in the face of weight loss, as if their bodies were bent on returning to obesity?