WE ARE not slaves to light after all. People have a second body clock, dictated by our need for food, which can overcome the light-activated circadian clock that’s supposed to control when we rise and sleep.
That, at least, is the opinion of Steven McKnight from the University of Texas Southwestern Medical Center in Dallas. He has found a clock system in the brain which he believes responds to how much food and energy is available, rather than night and day.
The clock is a protein, called NPAS2, which is mainly found in the forebrain. It controls the production of…
