A functioning circadian clock may help maximize weight loss following bariatric surgery

Prior research observations suggest that appropriate timing of calorie consumption and minimal disruption of the light/dark cycle set by the environment are crucial for a healthy energy balance and metabolism. However, little is known about the potential role of this molecular clock on maximizing the beneficial metabolic effects of bariatric surgery -- one of the most effective therapies available for obesity.

"Our findings from this mouse study suggest that patients with a disrupted circadian rhythm -- such as night-shift workers and those with night-eating syndrome -- may not be able to achieve the maximum amount of weight loss resulting from bariatric surgery," said the study's lead researcher Mohamad A. Mokadem, MD, ABOM, of the University of Iowa. "Our research shows that it could be important for patients to have a normal circadian clock pre-surgery to maximize weight loss following surgery."

The research implications for patients are drawn from a study conducted in mice, which is one of the first steps toward designing and replicating such a study in humans. Study authors say that more research is needed to better understand the role of circadian rhythm regulators or "clock genes" in the reversal of obesity, including research conducted in a patient population.

"Bariatric surgery has long been recognized as one of the most effective treatments for severe obesity," said Samer Mattar, MD, spokesperson for The Obesity Society and Professor of Surgery at Oregon Health and Science University. "This study is a step toward better understanding the underlying mechanisms affecting bariatric surgery outcomes, enabling us to continue to improve upon this form of treatment."

The Obesity Society reinforces that while bariatric surgery comes with risks, as does any surgery, it is a good option for some -- but not all -- patients.

"There are many options for patients with obesity from surgery to FDA-approved medications and weight-loss counseling," continued Dr. Mattar. "Patients with obesity should discuss their best options with a qualified obesity treatment specialist."