In experiments on mice, a team at the Salk Institute for Biological Studies in California found that eating while we stay up to browse the Internet or watch a late film is likely to be contributing to rising obesity levels.
Dr Satchidananda Panda, an associate professor who led the study, said at certain times of day the liver, intestines and muscles are at peak efficiency, while at other times they are "sleeping".
"Every organ has a clock. Those metabolic cycles are critical. When mice or people eat through the day and night, it can throw off those normal metabolic cycles," Dr Panda was quoted as saying by the Daily Mail.
In the study, the researchers allowed a group of mice to eat only during an eight-hour period, while a second group could graze on what they wanted all day and night.
They found that even though the two groups were eating about the same amount of calories, those who ate at set times during the day did not become obese.
The researchers explained that the mice who ate when they wanted gained weight because they disrupted their body clock -- and the same principle may apply to humans too.
At the end of their study, the mice that ate all day and night had 70 per cent more fatty deposits than the group that was time-restricted.
Noting that eating patterns have changed in recent years as people have more reasons to stay up into the night, Dr Panda suggested that restricting meal times could help to lower obesity levels.
Commenting on the study, published in the journal Cell Metabolism, Tam Fry of the National Obesity Forum said: "There's a pattern, which you should build up from childhood, of three set meals a day.
"Anything you do to upset that opens you up to problems with the hormones that control appetite."
