Eating at the right time is important for health, UTSW study shows
Time-restricted eating during a limited window each day reduced frailty, delayed disease onset and disability in preclinical model
DALLAS – June 25, 2026 – Cutting calories and limiting nighttime snacking are known to improve health and extend your lifespan. But would only eating during certain hours of the day have a similar effect on healthspan, which is the length of time a person is healthy and free from disease?
A new study from UT Southwestern Medical Center researchers suggests so. It found that restricting feeding to a window of time when healthy mice are normally active, at night, significantly improved their healthspan. The findings, published in Nature Aging, could lead to new strategies to achieve the same goal in humans, according to study leaders Joseph Takahashi, Ph.D., Chair and Professor of Neuroscience at UT Southwestern, and Carla Green, Ph.D., Professor of Neuroscience. Both are Investigators in the Peter O’Donnell Jr. Brain Institute.
This research suggests that circadian-aligned, timed feeding alone can meaningfully influence health during aging in mammals, the UT Southwestern authors said.
Human life expectancy has nearly doubled over the past century. However, Dr. Takahashi explained, healthspan remains limited, with many people spending more than 10% of their lives in poor health due to age-related functional declines and disease development. Research has shown that decreasing daily calorie consumption up to 50% can extend life in numerous model organisms while also delaying the onset of age-associated diseases such as cancer, cardiovascular disorders, and neurodegeneration.
A 2022 study in mice led by the Takahashi Lab and the Green Lab further revealed that combining 30% caloric reduction with restricted feeding during a short window at night, when mice are normally active, extended lifespan up to 35% and improved health compared with mice that ate as much as they wanted and whenever they chose. Since caloric restriction can be difficult to implement in people, Dr. Takahashi, Dr. Green, and their colleagues wondered whether just limiting the time when the animals ate might make a similar difference in healthspan and lifespan. Because their previous study focused on male mice, the scientists also wanted to see if there were sex-specific differences in the effects of this intervention.
To test this idea, the team worked with 528 healthy lab mice, half male and half female. For the first eight weeks of their lives, the animals ate as much as they wanted and whenever they wanted. After that, 108 mice of each sex continued this lifestyle while the rest were assigned to eat in either an eight- or 12-hour window at night. The researchers then tracked these animals for the rest of their lives, closely measuring their food intake, activity levels, body composition, and overall health.
Although the male mice eating in the eight-hour feeding window lived about 12% longer than mice allowed to free-feed, mice in the other time-restricted feeding (TRF) groups had no extension in lifespan. However, all the TRF animals had significant extensions in healthspan, with slower age-related increases in body weight, body fat, frailty, and the onset of age-related diseases.
While the most pronounced benefits occurred in the group restricted to an eight-hour feeding window, a 12-hour window was still sufficient to improve multiple measures of health over time. “Healthspans were extended in both sexes, but the benefits were more prolonged for females relative to their shorter lifespan,” Dr. Green said.
“Optimal times for people to eat would be during a 12-hour window beginning in the morning,” Dr. Takahashi said. Studies designed to test the effects of time-restricted eating in humans have had beneficial but mixed results, he said, potentially because of inconsistencies with the length and timing of the designated eating window and the health of participants. New clinical trials will be necessary to test whether eating in a restricted window during humans’ typical waking hours in the daytime could lead to similar healthspan benefits.
Other UTSW researchers who contributed to this study are co-first authors Samantha Iiams, Ph.D., postdoctoral researcher in the Takahashi Lab, and Nathan Skinner, Ph.D., Instructor of Neuroscience; and Mary Wight-Carter, D.V.M., Assistant Director of the Animal Resource Center Diagnostic Lab.
Dr. Takahashi holds the Loyd B. Sands Distinguished Chair in Neuroscience. Dr. Green is a Distinguished Scholar in Neuroscience.
This study was funded by grants from the Howard Hughes Medical Institute, the National Institutes of Health (NIH/NIA AG045795, NIH/NIA AG072736, NIH/NIGMS GM127122, NIH 1T32HL138438), and the Milky Way Research Foundation (MWRF210823).
About UT Southwestern Medical Center
UT Southwestern, one of the nation’s premier academic medical centers, integrates pioneering biomedical research with exceptional clinical care and education. The institution’s faculty members have received six Nobel Prizes and include 27 members of the National Academy of Sciences, 25 members of the National Academy of Medicine, and 13 Howard Hughes Medical Institute Investigators. The full-time faculty of nearly 3,400 is responsible for groundbreaking medical advances and is committed to translating science-driven research quickly to new clinical treatments. UT Southwestern physicians in more than 80 specialties care for more than 143,000 hospitalized patients, attend to more than 470,000 emergency room cases, and oversee nearly 5.3 million outpatient visits a year.