A new high-precision feeding system for lab mice reinforces the idea that the time of day food is eaten is more critical to weight loss than the amount of calories ingested.
Mice on a reduced calorie plan that ate only during their normal feeding/active cycle were the only ones among five groups to lose weight, despite consuming the same amount as another group fed during their rest time in daylight, according to the study at UT Southwestern Medical Center.
“Translated into human behavior, these studies suggest that dieting will only be effective if calories are consumed during the daytime when we are awake and active. They further suggest that eating at the wrong time at night will not lead to weight loss even when dieting,” said Dr. Joseph S. Takahashi, Chairman of Neuroscience at UT Southwestern’s Peter O’Donnell Jr. Brain Institute and Investigator with the Howard Hughes Medical Institute.
Using high-tech sensors and automated feeding equipment, scientists developed the feeding system to help answer the difficult question of why calorie-restricted diets improve longevity. They say the new set of tools has already offered fresh insights.
Among the findings published in Cell Metabolism, scientists documented how mice on a diet reduced their eating to a very short time period and were unexpectedly active during the day — the normal rest period for the nocturnal animals. These data reveal previously unknown relationships among feeding, metabolism, and behavior.
Besides affecting weight, scientists believe the timing of food consumption affects one’s circadian rhythms and may be the route by which dietary habits impact lifespan. The study reinforced this notion by testing the day/night cycles of mice under different feeding schedules.
This is an especially important factor for scientists to consider for future research, given that many calorie-reduction studies involve only daytime feeding, which is the wrong time for otherwise nocturnal mice.
Without accounting for the timing of food intake, research that examines the effects of calorie reduction on lifespan may be skewed by hidden factors such as lack of sleep and desynchronized circadian rhythms.
The report, materials of which have been provided by UT Southwestern Medical Center, was released in Science Daily.