Chronic overeating plays fundamental role in obesity epidemic

The causes of obesity are complex and individual, but it is clear that chronic overeating plays a fundamental role. But when this behaviour becomes compulsive and out of control, it is often classified as "food addiction" - a label that has generated considerable controversy, according to a McMaster University psychiatrist and obesity researcher.

In a commentary appearing in the Dec. 21, 2009, issue of the Canadian Medical Association Journal (CMAJ), Dr. Valerie Taylor, an assistant professor of psychiatry and behavioural neurosciences at McMaster and director of the Bariatric Surgery Psychiatry Program at St. Joseph's Healthcare Hamilton, and her co-authors argue that food addiction in some individuals may be a reality and needs to be considered in the management of weight problems.

"The concept of addiction is complex, and the delineation of its defining characteristics has fostered considerable debate," Taylor and her co-authors write. "Despite a lack of consensus, researchers nevertheless agree that the process involves a compulsive pattern of use, even in the face of negative health and social consequences."

Food addiction can be compared to other addictive behaviours, as both food and drugs can cause tolerance, or an increase in the amount required to achieve intoxication or satiety. Withdrawal symptoms such as mood changes can occur after discontinuing drugs or during dieting. As well, after gastric surgery for obesity, a subset of patients exhibit other addictive behaviours.

"The concept of addiction does not negate the role of free will and personal choice," Taylor and co-authors write. "It may, however, provide insight into why a some individuals with obesity continue to struggle."

The authors conclude that therapies traditionally applied to the area of addiction may be helpful in managing weight problems, which are often viewed through the same lens.

"The current 'blame' mentality that is often applied to individuals with obesity needs to be re-examined," the authors write. "Although medicine may not yet accept compulsive overeating as an addiction, we cannot ignore evidence highlighting the role played by biologic vulnerability and environmental triggers."