Obesity and binge eating: a disrupted clock in our body?

A UC, Lindner Center of HOPE study investigates the role of the circadian clock in obesity and eating behavior

The clocks on our walls, on the lock screens of our phones and attached to our wrists drive most actions in our lives. Time determines when we have to go to bed or wake up in the morning, when we need to be in class or at work and even when we feel the need to eat breakfast, lunch or dinner.

We also have inner, cellular clocks in most tissues of our body that are coordinated by a master circadian clock in the brain. These clocks form our circadian system that triggers some of these needs and responses, like getting tired and feeling hunger.

Now, researchers at the University of Cincinnati and the Lindner Center of HOPE are hosting a unique clinical trial to see if readjusting the circadian system of people with binge eating behavior can help in understanding more about why this occurs and develop new treatment options in the future. Scientists are using tabletop lamps and melatonin supplements to test their theory.

Binge eating behavior is a form of disordered eating characterized by excessive food consumption with a loss of control, causing a person to overeat in a relatively short period of time.

The associated Binge Eating Disorder, or BED, is characterized by recurrent episodes, without the compensatory behaviors observed in bulimia nervosa, meaning purging afterward. BED is the most prevalent eating disorder worldwide and affects an estimated 2.8 million people in the United States. It is frequently observed in individuals with obesity and those with other psychiatric diagnoses, like mood and anxiety disorders. Many are unaware that they have BED, and it remains undiagnosed. Additionally, treatment options are very limited.

Francisco Romo-Nava, MD, PhD, an assistant professor in the Department of Psychiatry and Behavioral Neurosciences at UC, associate chief research officer for the Research Institute at the Lindner Center of HOPE and a UC Health physician scientist, says little is known about how the circadian system in these patients impacts their eating patterns.

“The circadian system makes it possible for our body to adapt to day and night periods, which has profound effects on physiology and behavior beyond regulation of sleep and wake cycles,” he says. “The most powerful signals that synchronize our circadian system are the presence of daylight and the production of melatonin at night, which is the chemical signal of darkness.

“The circadian system is different for each person. For example, some people work better during the day while others do so at night. Some people skip breakfast, while others eat a large meal to start the day. Recent studies suggest that the circadian system may be involved in regulating our food choices, the time at which we eat and how much we eat. However, the involvement of the circadian system in disordered eating behavior, such as binge eating behavior, is not well understood.”

Romo-Nava says preliminary research has shown that those with binge eating disorder may have circadian system abnormalities, and that by targeting this system in the body, new interventions and treatments may be available for patients.

In this study, funded by the National Institute of Mental Health and housed at UC’s Lindner Center of HOPE, researchers will compare the circadian system function in 80 adults with obesity, 40 with binge eating disorder and 40 without, for two weeks. Participants will complete a sleep and eating behavior diary and wear a device — a watch — that measures activity patterns.

Their circadian phases will be assessed by determining surges in melatonin concentrations at the specific point in time when their brains and bodies shift into “night mode.”

Romo-Nava says, traditionally, studies such as this involved costly and inconvenient in-hospital or sleep lab assessments of melatonin concentrations in saliva samples under dim lights, mimicking dusk, to detect the time of the surge in melatonin production at night.

However, in this study, researchers are using a new approach, where participants can collect the saliva samples easily at home in a dimly lit room.   

Finally, researchers will test whether or not they can resynchronize study participants’ circadian system over the course of a month by combining morning light, mimicked by tabletop lamps, and the administration of a fixed dose of melatonin or placebo at night. The melatonin is given at times that are individualized according to each participants’ circadian phase. This phase of the study will only be conducted on individuals who have been diagnosed with binge eating disorder.

“We want to evaluate if this method can be an individualized way to study the circadian system in this condition,” Romo-Nava says. “But ultimately, we want to advance our understanding of the role of the circadian system in binge eating disorder, and this study will provide valuable insight on its potential as a new therapeutic target. We’re excited about how this could positively impact patients with binge eating disorder in the future.”

More about the study

Participants without binge eating will be paid up to $215 for completing four study visits that involve assessments and laboratory studies. Participants with BED will be paid up to $440 for completing study procedures, which also include an intervention study phase and a total of eight study visits. Payments will be made at the end of each study visit with a prepaid debit card. For more information, contact Brian or George at (513) 536-0707 or fill out a prescreening questionnaire.