Is Obesity an Addiction?Wednesday, March 17, 2010
Regular readers of these pages are well aware of the close link between addictions and some forms of overeating. This topic is now nicely addressed in a commentary by Valerie Taylor (McMaster, Hamilton), Claire Curtis and Caroline Davis (both York University, in this week’s edition of CMAJ.
As they discuss,
“The concept of food addiction, which more accurately may reflect addiction to specific components of food, can be described in much the same way as other addictive behaviours. Both food and drugs induce tolerance over time, whereby increasing amounts are needed to reach and maintain intoxication or satiety. In addition, withdrawal symptoms, such as distress and dysphoria, often occur upon discontinuation of the drug or during dieting. There is also a high incidence of relapse with both types of behaviour.“
To further support their arguments, they cite the many imaging studies showing that specific areas of the reward or mesolimbic system, such as the caudate nucleus, the hippocampus and the insula, are activated both by drugs and by food.
Thus, the easy accessibility of highly palatable foods together with our innate preferences for such foods, can increase the likelihood that vulnerable people will “misuse” food, in much the same way that addicts misuse other drugs to blunt negative emotional states, such as depression, anxiety, loneliness, boredom, anger orinterpersonal conflict.
While the concept of addiction should not negate the role of free will and personal choice, it does provide a rationale for the including addiction screens as a routine part of assessment for obesity. It may also help explain the success of lifestyle programs that incorporate pharmacotherapy or behavioural strategies specifically designed to address the addictive component of this illness.
Thus, as pointed out by Taylor and colleagues, there is not only considerable overlap among the medications shown to interfere with food and drug abuse in animal models, but the many behavioural interventions developed for managing addictions (motivational interviewing, cognitive behavioural therapy and 12-step programs), are increasingly recognised as also being helpful in managing obesity.
Health professionals and decision makers charged with tackling the obesity epidemic would do well to familiarise themselves with the science of addictions and utilize learnings from addiction management in their counseling of patients presenting with excess weight.