Consuming meals within an 8-hour time frame each day leads to better organ function in mice.
The finding reveals how intermittent fasting 鈥� or cycling between periods of fasting and eating 鈥� may improve health, says at the Salk Institute for Biological Studies in La Jolla, California.
Panda and his colleagues divided about 200 young male mice into two groups and fed each a high-fat, high-sugar diet with the same total number of calories. One group was restricted to eating within an 8-hour time window, while the other could feed freely. After four weeks, the researchers collected tissue samples from 22 organs in the mice, including the gut, brain and liver, as well as fat tissue, and analysed gene expression in each to measure organ function.
Advertisement
The study, which is under review, found that a time-restricted diet improved organ functions, such as digestion and fat storage, by influencing when genes were activated.
Compared with mice that could feed whenever they wanted, those that could only eat during the restricted 8-hour window saw significant improvements in gene activation: 70 per cent of the genes in at least one organ changed their expression. Fat and digestive tissues saw the greatest improvements.
鈥淲e always think that some genes are beneficial and some genes are bad, but it鈥檚 not about good or bad. It鈥檚 about what time they come on,鈥� says Panda. That is because each organ follows its own internal clock that determines when to switch between functions.
Take the gut for example. During the day, a set of genes turns on to digest food, but at night, a separate set activates to repair the gut鈥檚 lining. These two sets can鈥檛 be active at the same time because the gut can鈥檛 perform these functions simultaneously, says Panda. The same is true for genes in the heart, liver and dozens of other organs, he says.
鈥淲hat we find is time-restricted feeding helps robustly regulate our circadian rhythm,鈥� he says.
Panda believes the study suggests a potential mechanism for how intermittent fasting may benefit humans, too. 鈥淚t鈥檚 really amazing that a very simple idea, like when to eat, gives us that superpower to optimise thousands of genes in different organs at the right time,鈥� he says.
The research was presented this month at the online American Society for Nutrition conference.
Sign up to our free Health Check newsletter for a round-up of all the health and fitness news you need to know, every Saturday
