A new study found that eating within consistent daytime windows improved several measures of healthy aging in mice.
Researchers compared unrestricted eating with 12-hour and eight-hour time-restricted feeding schedules over the animals' lifetimes.
The findings suggest meal timing may influence healthspan, although more research is needed to determine whether the same effects occur in people.
Most nutrition advice focuses on what to eat, but scientists are increasingly interested in when meals happen.
A new study from researchers at UT Southwestern explored whether limiting food intake to a consistent daily eating window could influence how animals age. Rather than changing the type of food the animals ate, researchers adjusted only the timing of meals so they aligned with the mice's natural active period.
The goal was to better understand whether eating in sync with the body's internal clock, known as the circadian rhythm, could affect long-term health. While the findings are promising, the researchers emphasize that the study was conducted in mice, so additional research will be needed before the results can be applied to people.
How the study was conducted
The researchers followed hundreds of genetically diverse male and female mice throughout their lives. All of the animals ate the same standard diet, but they were divided into three feeding schedules. One group had unrestricted access to food at all times. A second group was allowed to eat during a 12-hour daily window that matched the animals' normal active period. The third group ate during a more restrictive eight-hour window, also aligned with their circadian rhythms.
Over time, the team monitored a wide range of health measures, including body weight, body composition, activity patterns, frailty, glucose regulation, disease development, and lifespan.
They also created a composite "healthspan index" that combined multiple measures of physical health to provide a broader picture of how well the animals aged rather than focusing only on how long they lived.
What the researchers found and what it means
Both time-restricted feeding schedules improved several markers of healthy aging compared with unrestricted eating.
Mice in the timed-feeding groups generally maintained healthier body composition, showed lower frailty scores, and had better overall healthspan scores as they aged. The benefits were strongest in the eight-hour feeding group, although the effects differed between males and females.
Notably, male mice in the eight-hour group experienced a roughly 12% increase in median lifespan, while female mice did not see a significant lifespan extension.
Even so, female mice still showed improvements in healthspan, meaning they remained healthier for a greater portion of their lives despite not living longer.
The researchers concluded that eating in alignment with the body's internal clock may promote healthier aging in mammals, but they caution that these findings do not yet show the same benefits would occur in humans. Future studies will be needed to determine whether similar meal-timing strategies can improve healthy aging in people.