A new study shows how indulging in holiday treats can leave people with a disturbed "food clock" that can lead to many health complications. It is this disturbed clock that can make you feel like you have a jet-lag during the holiday break.

Organisms, including humans, have a complex mechanism called circadian oscillator that co-ordinates various functions in the body. Previous research has shown that in mammals, the mechanism is controlled by a tiny spot in the brain known as the "superchiasmatic nucleus."

The food clock is there to help our bodies increase nutritional intake. The clock controls genes that help the absorption of nutrients in our digestive tract as well as their distribution in the blood stream. The clock also anticipates our eating habits and makes us feel impatient just before meal-time.

Although, previous studies have shown that large meals at unusual time of the day can reset the clock, this is the first time that researchers were able to identify the genetic mechanism involved.

The research team from University of California, San Francisco, found that a protein called PKCγ helps in resetting the food clock when there is a change in the eating pattern.

The study showed that when mice are given regular meals at a particular time, they adjust their biological clock according to the meal-time. However, mice that lack the protein PKCγ have no hunger pangs before the meal time and do not respond to any changes in the diet routine.

The study may help explain how changes in meal time affect the body's metabolism. Researchers say that the study might explain why people who work night-shifts tend to put on more weight than people who work during day time.

"Understanding the molecular mechanism of how eating at the "wrong" time of the day desynchronizes the clocks in our body can facilitate the development of better treatments for disorders associated with night-eating syndrome, shift work and jet lag," Louis Ptacek, MD, the John C. Coleman Distinguished Professor of Neurology at UCSF and a Howard Hughes Medical Institute Investigator.

The study is published in the journal Proceedings of the National Academy of Sciences.