LOS ANGELES (Dispatches)-- Researchers found evidence that fasting affects circadian clocks in the liver and skeletal muscle, causing them to rewire their metabolism, which can ultimately lead to improved health and protection against aging-associated diseases.
"We discovered fasting influences the circadian clock and fasting-driven cellular responses, which together work to achieve fasting-specific temporal gene regulation," said lead author Paolo Sassone-Corsi, Donald Bren Professor of Biological Chemistry at University of California’s  School of Medicine. "Skeletal muscle, for example, appears to be twice as responsive to fasting as the liver."
The circadian clock operates within the body and its organs as intrinsic time-keeping machinery to preserve homeostasis in response to the changing environment. And, while food is known to influence clocks in peripheral tissues, it was unclear, until now, how the lack of food influences clock function and ultimately affects the body.
The research was conducted using mice, which were subjected to 24-hour periods of fasting. While fasting, researchers noted the mice exhibited a reduction in oxygen consumption (VO2), respiratory exchange ratio (RER), and energy expenditure, all of which were completely abolished by refeeding, which parallels results observed in humans.