You probably pay attention to what you eat. But new research suggests when you eat could be just as important for staying healthier as you age.

A new study from researchers at UT Southwestern Medical Center, published in the journal Nature Aging, found that limiting food intake to a consistent daily eating window significantly improved healthspan—the number of years spent healthy and free of disease—in mice.

Unlike calorie restriction, which can be difficult to maintain, the animals were allowed to eat as much as they wanted during either an eight- or 12-hour feeding window. Researchers then tracked more than 500 mice throughout their lives.

Here’s What Happened When Researchers Limited Eating to Certain Hours

The results were striking. Mice that followed time-restricted feeding experienced slower gains in body fat, reduced frailty, delayed onset of age-related diseases, and better overall health compared with mice that ate around the clock. Male mice eating within an eight-hour window also lived about 12% longer.

“Our research suggests that circadian-aligned timed feeding alone can meaningfully influence health during aging in mammals,” the study authors wrote.

According to senior author Joseph Takahashi, PhD, Chair of Neuroscience at UT Southwestern, the findings point to meal timing as a promising strategy for improving healthy aging without requiring people to drastically cut calories.

The Best Time to Eat May Surprise You

While mice naturally eat at night, Dr. Takahashi said the equivalent for humans would likely be eating during a roughly 12-hour window that begins in the morning, aligning meals with the body’s natural circadian rhythm.

The researchers caution that the findings don’t yet prove the same benefits occur in people. Previous human studies on time-restricted eating have produced mixed results, and Dr. Takahashi said more clinical trials are needed to determine the ideal eating window and whether it can meaningfully extend human healthspan.

Still, if future research confirms these findings, your longevity plan may depend as much on when you eat as what’s on your plate.

Related: Here’s What to Know About New U.S. Dietary Guidelines That Take Aim at Processed Foods

This story was originally published by Men’s Journal on Jun 25, 2026, where it first appeared in the Nutrition section. Add Men’s Journal as a Preferred Source by clicking here.