When you eat may be as important for heart health as what you eat, research suggests.
Scientists found that fruit flies fed for 12 hours a day slept better, gained less weight and had much healthier circulatory systems than those allowed to eat at any time.
The effect appeared to be linked to body clock genes that exist in all kinds of animals, including humans.
Previous research has indicated that late night snacks may be bad for the heart. People who tend to eat late and at night are more at risk of heart disease than those who finish their meals earlier.
In the study, one group of fruit flies was given a standard diet of cornmeal and allowed to feed all day long while another had access to food for just 12 hours a day.
After three weeks, the flies on the time-restricted diet appeared far healthier than their ‘eat any time’ counterparts.
Lead scientist Shubroz Gill, who led the research at San Diego State University (SDSU) in the US, said: “In very early experiments, when we compared five-week-old flies that were fed for either 24 hours or 12 hours, the hearts of the latter were in such good shape that we thought perhaps we had mistaken some young three-week-old fruit flies for the older group.
“We had to repeat the experiments several times to become convinced that this improvement was truly due to the time-restricted feeding.”
Other experiments showed that older flies benefited from time-restricted meals as well as younger flies.
Three genetic pathways appeared to be involved in the effect, further studies showed.
One was linked to a ‘suite’ of genes responsible for circadian rhythm, the natural body clock that ties biological processes to night and day cycles.
Mutant flies with non-functional circadian rhythm genes gained no advantage from time-restricted feeding.
The two other gene pathways influenced protein folding – which allows the molecules to function – and metabolism.
“If and how these three pathways all work together, we don't yet know entirely,” said Girish Melkani, also from SDSU.
The research, published in the journal Science, may be relevant to humans according to the researchers, who also stress the need for caution when extrapolating results from insects.
Melkani said: “Time-restricted feeding would not require people to drastically change their lifestyles, just the times of day they eat. The take-home message then would be to cut down on the late-night snacks.”