Thinner Mice March to Mealtime Rhythm


Rather than count calories, people who want to lose weight may want to count minutes.

Investigators led by Satchidananda Panda at the Salk Institute for Biological Studies offered the same high fat diet to two groups of mice. The first group could access the food only eight hours a day, while mice in the other group could hit the rodent buffet whenever they wanted.

The study, reported in the journal Cell Metabolism, found the mice on the time-restricted diet consumed just as much food as those with “ad lib” food access, yet had lower rates of obesity, excessive insulin, excessive fats in the liver, and inﬂammation, as well as improved motor coordination.

When we restrict eating to a schedule, organs like the liver “turn on” to process new chemicals from food, then “turn off” afterwards, entering a metabolic trough. In theory, the study argues, the mice that ate eight hours each day allowed their organs to process nutrition more efficiently. Mice who snacked whenever they wanted -- like modern humans often do -- prevented the body from establishing a proper metabolic rhythm.

“The focus has been on what people eat,” said Panda, in the team’s announcement of the study. “We don’t collect data on when people eat.”

The study’s authors compared diet to sleep. If you sleep eight hours, but in fits and starts throughout the day, you never feel rested. Similarly, even an apple may bring less benefit at 3 a.m. than it would at noon.