Sept. 6 (UPI) -- By increasing fasting times between meals, male mice were healthier and lived longer compared with rodents who ate more frequently, according to a study.
The improved health and longevity occurred regardless of the amount of calories consumed, according to researchers with the National Institutes of Aging, the University of Wisconsin-Madison and the Pennington Biomedical Research Center, Baton Rouge, La. They published their findings Thursday in the journal Cell Metabolism. The NIA is part of the National Institutes of Health.
"This study showed that mice who ate one meal per day, and thus had the longest fasting period, seemed to have a longer lifespan and better outcomes for common age-related liver disease and metabolic disorders," Dr. Richard J. Hodes, the NIA director, said in a press release. "These intriguing results in an animal model show that the interplay of total caloric intake and the length of feeding and fasting periods deserves a closer look."
The increased fasting times perhaps "enables repair and maintenance mechanisms that would be absent in a continuous exposure to food," lead author Dr. Rafael de Cabo, chief of the Translational Gerontology Branch of the NIA Intramural Research Program, said.
In the study, 292 male mice were divided into two diet groups. In one group, mice received a naturally sourced diet that was lower in purified sugars and fat, but higher in protein and fiber than the other diet.
Each diet group was subdivided into three methods of access to food: food around the clock, 30 percent fewer calories per day and a single meal that added up to the same number of calories as the group with food always available.
The meal-fed and calorie-restricted mice learned to eat quickly, resulting in longer daily fasting periods for both groups.
The mice's metabolic health was tracked through their lifespans until their natural deaths.
Meal-fed and calorie-restricted mice had improved overall health, as evidenced by delays in common age-related damage to the liver and other organs, and extended longevity.
The calorie-restricted mice also had significant improvements in fasting glucose and insulin levels compared with the other groups.
Diet composition had no significant impact on lifespan in the meal-fed and calorie-restricted groups.
Although caloric restriction has been studied for more than a century, de Cabo said the impact of increased fasting times has only recently been further scrutinized.
The researchers next want to study other strains of mice and lab animal species using both sexes. They also find to see how this relates to humans.