Published: Nov 14, 2013 | Updated: Nov 15, 2013
By Kristina Fiore, Staff Writer, MedPage Today

Full Story:  http://www.medpagetoday.com/MeetingCoverage/ObesityWeek/42913

ATLANTA — Although it’s not technically an addictive disorder by psychiatric standards, behaviors associated with “food addiction” are closely tied to obesity, researchers reported here.

In an analysis of data from the Canadian province of Newfoundland, about 5% of people there exhibited symptoms of “food addiction,” as classified by the Yale Food Addiction Scale, Pardis Pedram, MD, MSc, of Memorial University in Newfoundland, and colleagues reported at Obesity Week here.

That prevalence rose with increasing obesity, Pedram said, from 1.6% among those who were underweight or normal weight to 7.7% in overweight and obese patients.

The data “provide strong evidence that food addiction may represent a distinct etiology of human obesity in the general population,” she said during an oral presentation.

Previous research has suggested that “food addiction” shares similar neurobiological and behavioral components with other substance use disorders. But in the latest revision of the Diagnostic and Statistical Manual of Mental Disorders (DSM-5) — the psychiatrist’s holy grail of bona fide diagnoses — “food addiction” did not make the cut.

Even though it’s not listed under “behavioral addictions,” it does, however, fit the bill for “binge eating disorder,” which is included in the latest edition of the DSM, experts say.

Compared with psychiatrists, obesity experts are more likely to accept that binge eating is an addictive disorder. Indeed, the Yale Food Addiction Scale was recently developed and validated in order to provide a diagnostic tool.

Ashley Gearhardt, PhD, who developed the scale and is now at the University of Michigan, said that although binge eating disorder isn’t currently considered to be caused by an addictive process, “behavioral and biological evidence continue to link addiction and compulsive eating behavior.”

David Katz, MD, MPH, director of the Yale Prevention Research Center, called the debate over food addiction one of “semantics and technicalities.”

Although food may not meet the full “letter of the definition for addiction,” Katz told MedPage Today, “it fully meets the ‘spirit’ of the definition, and more, in all ways that matter.”

That includes the fact that food has effects on the nervous system and can exert effects such as cravings and tolerance, he said.

“The system we now refer to as ‘addiction’ is actually all about rewarding and reinforcing behaviors that fostered survival,” Katz said. “All addictions other than food and sex are misdirecting a system laid down by natural selection to encourage us to keep ourselves alive, and pass our genes along to the next generation.”

To assess the prevalence of “food addiction” among the population of Newfoundland and to determine whether the condition had ties to obesity, Pedram and colleagues assessed 652 participants — 415 women and 237 men, all of whom were over age 19.

They used the Yale Food Addiction Scale to assess behavior, while macronutrient intake was determined by the Willet Food Frequency Questionnaire.

Obesity was evaluated by body mass index (BMI) and by body fat percentage as measured by dual-energy x-ray absorptiometry (DEXA) scans.

Overall, they found that the prevalence of “food addiction” was 5.4% — but it was higher in women than in men (6.7% versus 3%), translating to a significantly higher risk of “food addiction” in women (RR 2.28, P=0.046).

Pedram and colleagues also found that the prevalence of “food addiction” rose with increasing obesity, from 1.6% among underweight and normal weight patients to 7.7% among those who were overweight or obese.

Further analyses also revealed that obese and overweight women had a significantly higher risk of exhibiting addictive behaviors with food than obese or overweight men (RR 3.50,P=0.002).

Pedram noted that patients who met criteria for food addiction weighed, on average, 11.7 kg (25.8 lbs) more than those who were not addicted, and they took in a higher percentage of calories from fat and protein.

She concluded that their findings suggest food addiction may represent a distinct etiology for obesity, but that further studies in a larger population are needed to confirm the findings.

Gearhardt said the study is a “huge step forward in evaluating the potential consequences of addictive-like eating.”

“We need to identify addictive-like eaters prior to understanding whether an addictive process is contributing to the problem,” she said.