Biological clocks regulate processes throughout the body. Nearly every tissue and organ contains biological clocks. They are usually triggered by certain proteins.

There is one master clock that coordinates/regulates all the other little clocks. In humans this is a small center in the brain called the superchiasmatic nucleus (SCN).

Circadian rhythm: https://www.sleepfoundation.org/circadian-rhythm

Circadian rhythm fact sheet https://www.nigms.nih.gov/education/fact-sheets/Pages/circadian-rhythms.aspx

Time restricted eating: https://www.foundmyfitness.com/topics/time-restricted-eating

Satchin Panda, Ph.D. on Time-Restricted Feeding and Its Effects on Obesity, Muscle Mass & Heart Health: https://www.foundmyfitness.com/episodes/satchin-panda