Yet another study suggests that humans are meant to eat at certain times of day - emphasis on day.
Studies on the human clock show that our bodies have natural tendencies for when we should eat, sleep and be active. The eating and activity seem to blend well with daylight hours.
During the day, certain hormones and other body chemicals are released that promote eating and activity.
At night, hormones shift to encourage sleep.
A study of mice shows the consequences of mixing up that pattern.
Researchers at Northwestern University found that mice that were fed a high-fat diet during normal sleeping hours gained 48 percent more weight than mice eating the same type and amount of food during their naturally wakeful hours. Those mice gained 20 percent beyond their weight at the start of the study.
"How or why a person gains weight is very complicated, but it clearly is not just calories in and calories out," Fred Turek, the lead author of the study, said in a news release. "We think some factors are under circadian control. Better timing of meals, which would require a change in behavior, could be a critical element in slowing the ever-increasing incidence of obesity."
This dynamic might explain why shift workers appear prone to weight gain, said a co-author of the paper, Deanna M. Arble.
"Their schedules force them to eat at times that conflict with their natural body rhythms," she said.
The study was published online this week in the journal Obesity.