Researchers in Guangzhou, China, tested that idea directly. They randomized 139 adults with obesity to either an 8-hour eating window with a calorie limit, or the same calorie limit spread across the whole day, and followed both groups for a year.
After 12 months, the time-restricted group had lost about 8 kilograms and the calorie-only group about 6.3 kilograms, a difference too small to be statistically significant. Blood pressure, blood sugar and cholesterol improved by similar amounts in both groups.
The eating window added no measurable benefit once total calories were matched between groups. Smaller trials before it had hinted at an edge for time-restricted eating, but this was the largest and longest head-to-head test, run at a single center in China, and it found the clock mattered far less than the plate.
Read the original study
The calories did the work, not the clock.
Source
- Liu, D., Huang, Y., Huang, C., Yang, S., Wei, X., Zhang, P., Guo, D., Lin, J., Xu, B., Li, C., He, H., He, J., Liu, S., Shi, L., Xue, Y., & Zhang, H. (2022). Calorie Restriction with or without Time-Restricted Eating in Weight Loss. New England Journal of Medicine, 386(16), 1495–1504. https://doi.org/10.1056/nejmoa2114833