People who work the nightshift or odd hours and eat at irregular times are more prone to weight gain and diabetes, likely due to eating patterns not timed with natural daylight and when people typically eat. But is it possible to stave off the ill effects of eating at these "unusual" times despite it not being biologically preferable? A new study from the Perelman School of Medicine at the University of Pennsylvania says 'yes', and sheds light on how the body knows when to eat. The study, published today in Science, explains how researchers discovered a connection between the liver's internal clock and feeding centers in the brain.

The team's research showed that the liver sends signals to the brain via the vagus nerve, letting the brain know if eating is happening at a time that follows the body's circadian rhythm. These signals can get disrupted from working unusual hours. The brain then overcompensates, leading to overeating at the wrong times.

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. This feedback is through a nerve connection from the liver to the brain". Mitchell Lazar, MD, PhD, study's senior author, director of Penn Medicine's Institute for Diabetes, Obesity, and Metabolism, and the Ware Professor of Diabetes and Metabolic Diseases Researchers specifically targeted genes called REV-ERBs in the liver cells of mice.

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