The obesity epidemic and food addiction: clinical similarities to drug dependence.

As of 2010 nearly 70% of adult Americans were overweight or obese. Specifically, 35.7% of adult Americans are obese, and this is the highest level of obesity in the recorded history of the United States. A number of environmental factors, most notably the number of fast food outlets, have contributed to the obesity epidemic as well as to the binge prone dynamic. There is evidence that bingeing on sugar-dense, palatable foods increases extracellular dopamine in the striatum and thereby possesses addictive potential. Moreover, elevated blood glucose levels catalyze the absorption of tryptophan through the large neutral amino acid (LNAA) complex and its subsequent conversion into the mood-elevating chemical serotonin. There appear to be several biological and psychological similarities between food addiction and drug dependence including craving and loss of control. Nonetheless there is at least one apparent difference: acute tryptophan depletion does not appear to induce a relapse in recovering drug-dependent individuals, although it may induce dysphoria. In some individuals, palatable foods have palliative properties and can be viewed as a form of self medication. This article will examine environmental factors that have contributed to the obesity epidemic, and will compare the clinical similarities and differences of food addiction and drug dependence.