Fat Cells Retain Molecular Memory of Obesity, Driving Weight Regain
New research published in Cell Reports reveals that fat cells retain a molecular memory of obesity, continuously signaling hunger via the asprosin hormone even after weight loss.
Maintaining weight loss is often harder than the initial diet, and new research published in Cell Reports explains why. Scientists discovered a molecular mechanism in fat cells that continues to signal hunger to the brain even after weight loss or the discontinuation of weight-loss medications. The findings reveal that obesity is not merely temporary excess weight, but a condition that leaves a lasting biological memory.
The Molecular Hunger Switch
Researchers at the Harrington Discovery Institute at University Hospitals (UH) and Case Western Reserve University identified a biological mechanism driving two major phenomena: the difficulty in preventing weight regain and how a predisposition to obesity is transmitted from mother to child. The study points to a molecular memory—chemical modifications within fat cells—that persistently stimulates appetite. At the center of this process is asprosin, a hormone secreted by fat tissue that signals the brain to stimulate appetite.
Imagine having an appetite-stimulating signal stuck in the 'on' position day after day, despite having lost weight, explained Dr. Atul Chopra, senior author of the study and professor of medicine and genetics. Our findings point to one reason why preventing weight regain is so difficult after treatment ends, and that same signal can be transmitted from mother to child via the placenta, predisposing the child to obesity.
Implications for Future Treatments
In experiments on mice, researchers identified a signaling protein called TGF-β1 that triggers increased asprosin production. Even after the mice shed their excess weight and TGF-β1 levels normalized, their fat cells continued producing elevated amounts of asprosin, keeping appetite high. This mechanism explains why GLP-1 medications do not erase the underlying biological memory, leading to renewed hunger once treatment stops. Blocking this biological pathway in mice successfully prevented both weight regain and the intergenerational transmission of obesity, paving the way for potential human therapies.
