Nighttime snacking and junk food cravings may contribute to unhealthy eating behaviors and represent a potential link between poor sleep and obesity, according to a study by University of Arizona Health Sciences sleep researchers.

The study was conducted via a nationwide, phone-based survey of 3,105 adults from 23 U.S. metropolitan areas. Participants were asked if they regularly consumed a nighttime snack and whether lack of sleep led them to crave junk food. They also were asked about their sleep quality and existing health problems.

About 60 percent of participants reported regular nighttime snacking and two-thirds reported that lack of sleep led them to crave more junk food.

The researchers found that junk food cravings were associated with double the increase in the likelihood of nighttime snacking, which was associated with an increased risk for diabetes. They also found that poor sleep quality seemed to be a major predictor of junk food cravings, and that junk food cravings were associated with a greater likelihood of participants reporting obesity, diabetes and other health problems.

"Laboratory studies suggest that sleep deprivation can lead to junk food cravings at night, which leads to increased unhealthy snacking at night, which then leads to weight gain. This study provides important information about the process, that these laboratory findings may actually translate to the real world," noted Michael A. Grandner, PhD, MTR, UA assistant professor of psychiatry and director of the UA Sleep and Health Research Program and the UA Behavioral Sleep Medicine Clinic. "This connection between poor sleep, junk food cravings and unhealthy nighttime snacking may represent an important way that sleep helps regulate metabolism."

"Sleep is increasingly recognized as an important factor in health, alongside nutrition," said Christopher Sanchez, UA undergraduate nutrition and dietetics major, who is the lead author of the study and a student research assistant in the Sleep and Health Research Program directed by Dr. Grandner. "This study shows how sleep and eating patterns are linked and work together to promote health."

William D. "Scott" Killgore, PhD, UA professor of psychiatry, medical imaging and psychology, and director of the UA Social, Cognitive and Affective Neuroscience (SCAN) Lab, also contributed to the study.

UA Health Sciences sleep researchers work as interdisciplinary teams, conducting research and leading clinical trials to assess how sleep affects memory, mental health, stress, alertness and decision-making, and how environmental factors affect sleep. Sleep and wakefulness disorders affect an estimated 15 to 20 percent of U.S. adults, according to the U.S. Department of Health and Human Services.

The research abstract, "Nighttime Snacking: Prevalence and Associations With Poor Sleep, Health, Obesity, and Diabetes," will be presented at SLEEP 2018, the 32nd annual meeting of the Associated Professional Sleep Societies LLC (APSS), which is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society, June 2-6 in Baltimore. The meeting is the world's premier forum to present and discuss the latest developments in clinical sleep medicine and sleep and the roughly 24-hour cycle that influences physiology and behavior, known as circadian science.