Eating at odd hrs muddles body clock, raises risk of obesity, diabetes: Study

Eating at odd hours—a common pattern among shift workers and frequent travelers—can lead to obesity and metabolic disorders such as diabetes, according to a new study by scientists who have discovered a previously unknown communication channel between the liver and brain.

- Rhythma Kaul

The research by a team from Perelman School of Medicine at the University of Pennsylvania, and published in Science, reveals that the liver contains its own biological clock that sends precise signals to the brain through the vagus nerve, helping regulate when we feel hungry and choose to eat.

When this delicate timing mechanism is disrupted, it can trigger a cascade of metabolic disturbances that may contribute to weight gain and other health problems.

The insights were uncovered in experiments on mice. Researchers focused on a family of genes called REV-ERBs in liver cells. These genes play a crucial role in maintaining circadian rhythm—the body's internal 24-hour clock that governs everything from sleep cycles to hormone release.

"Both mice and humans normally eat at times when they are awake and alert, and this circuit provides feedback from the liver to the central clock in the brain that keeps the system running smoothly," said Dr. Mitchell Lazar, director of Penn Medicine's Institute for Diabetes, Obesity, and Metabolism, and the study's senior author. "This feedback is through a nerve connection from the liver to the brain."