Complex and Confounding: Nighttime Eating Disorders Escape Easy Identification

The mysteries of the night have been fodder for fiction writers, storytellers, and myth-makers for centuries. But in the past few decades, scientists have turned their attention to the midnight hour in an attempt to understand two rare disorders that affect eating habits and sleep patterns.

NIGHT EATING SYNDROME

Night Eating Syndrome (NES) is an eating disorder with two primary components: excessive eating in the evening hours, and a tendency to awaken multiple times throughout the night to eat more. It is believed to occur in 1 to 2 percent of the general population, though among obese individuals, the estimated prevalence rises up to as much as 10 percent.

In 2003, Dr. Albert Stunkard, who first identified NES in 1955, announced that NES is the result of a significant disruption in one of an individual's internal body clocks.

"The circadian rhythm of food intake is extremely disturbed and the timing is delayed by four or five hours compared to that in normal people," Stunkard told WebMD Health News in an Oct. 16, 2003 article. NES, Stunkard said, is "the first clinical disorder to manifest different circadian rhythms of two biological systems."

Typically waking up with little or no appetite (and often feeling guilt or anger as a result of their previous night's intake), NES sufferers delay the majority of their eating until the end of the day.

According to ANRED (Anorexia Nervosa and Related Disorders, Inc.), NES manifests itself through the following behaviors and emotions:

• Not eating the first meal of the day until several hours after awakening.
• Eating more than half of one's daily intake between dinner and
• breakfast time.
• Eating more food after dinner than during the meal itself.
• Waking up to snack during the night.
• Experiencing guilt and shame while eating.

For an individual to be diagnosed with NES, these patterns of behavior - which in many cases are thought to be triggered by anxiety and accompanied by depression - must have lasted for two months or more.

Though NES can occur in anyone, a Jan. 2, 2006 article on the ScienceDaily website reported that researchers with the University of Pennsylvania and the University of Minnesota had documented an association among NES, obesity, and substance abuse in people who were suffering from psychiatric disorders.

Based upon evaluations of 399 patients of psychiatric outpatient clinics, the universities' research teams determined that those who were obese were five times more likely to be afflicted with NES than were non-obese patients. The rate of substance abuse among NES patients was found to exceed 30 percent - more than triple the prevalence among those who didn't have the condition.

"Night eating syndrome is often associated with life stress and depression, so we were particularly interested in looking at the prevalence of the condition in this population," the study's lead author, Jennifer D. Lundgren, PhD, said in a release that accompanied publication of the team's findings.

NOCTURNAL SLEEP-RELATED EATING DISORDER

Similar to, but perhaps even more confounding than NES is a condition known as Nocturnal Sleep-Related Eating Disorder (NSRED). Part sleep disorder and part eating disorder, NSRED is a relatively unknown (and widely misunderstood) condition in which affected individuals binge eat after falling asleep, often awakening with no memory of having done so.

In a manner akin to sleepwalking, people who have NSRED may leave their beds, find (and eat) food in other rooms, then climb back under the covers - all without ever having truly awakened.

The Merck Manual of Diagnosis and Therapy describes NSRED in the following manner: "The night-eating syndrome consists of morning anorexia, evening hyperphagia (excessive ingestion of food), and insomnia. Attempts at weight reduction in the presence of these ... conditions are inordinately difficult and may subject the patient to unnecessary distress."

Nancy Jordan, who told CNN reporter Rea Blakey that she has been a "sleep eater" for more than four decades, said that the types and amounts of food she eats is simply beyond her control.

"I can go through a loaf of bread a night," Jordan told Blakey for her July 2, 2002 article. "Peanut butter, I eat that [by] the spoonful. I've taken dry cereal to bed with me. Tomatoes out of the can. Margarine ... Pickles. Diet salad dressing. Frozen pizza, frozen chicken breasts and ice cream."

NSRED was first diagnosed in 1991, but even experts are unsure why or how people become afflicted with the disorder. Associations have been made with sleep apnea, restless leg syndrome, drug/alcohol withdrawal, and use of the sleep aid Ambien, but no conclusive cause-effect relationship has yet been established. 

In addition to consuming an excessive amount of calories, NSRED sufferers also face a variety of other risks, experts have noted.

"We are talking about messy, indiscriminate, and chaotic eating," researcher Lea Montgomery, RN, told WebMD writer Denise Mann, noting that unconscious eating can result in choking, burning, cutting, and otherwise injuring oneself while preparing and eating food. "It's very primitive and certainly not fine dining," she said.

In an article that appeared in the November 2006 edition of the journal Psychiatry MMC, Dr. R. Robert Auger wrote, "More than 65 percent of these patients ingest unpalatable substances, such as frozen foods and buttered cigarettes. Injuries from careless food preparation occur in approximately one-third of patients."

GETTING HELP

Because of the relative rarity of both NES and NSRED, and because both may be caused or exacerbated by a variety of underlying conditions, being diagnosed with and effectively treated for these disorders can be a challenging and complex process.

Common approaches include stress-management instruction, cognitive-behavioral therapy, lifestyle changes (such as adapted diets), and medications including dopamines, benzodiazepines, and selective serotonin reuptake inhibitors.

Individuals who suspect that they or someone they know is afflicted with a night eating disorder should consult with their health care provider to determine the proper course of treatment. Online, websites such as Something Fishy and the Eating Disorders Help Guide offer a wealth of information about eating disorders, including symptoms, causes and effects, tips for talking to a friend or loved one, and treatment options.