Study Compares Overeating to Drug Addiction
A recent study has reportedly likened overeating to a drug addiction, concluding that rats given access to high-fat food exhibited a neurochemical dependency similar to the “reward homeostasis induced by cocaine or heroin.” Paul Johnson and Paul Kenny, “Dopamine D2 Receptors in Addiction-Like Reward Dysfunction and Compulsive Eating in Obese Rats,” Nature Neuroscience, March 28, 2010. Researchers monitored the brains of rats divided into three groups: the first allowed unlimited access to high-fat foods; the second given access to high-fat fare for only one hour per day; and the third fed rat chow only. While the rats in the second group acquired a pattern of compulsive binge eating, consuming 66 percent of their daily calories during the one hour when high-fat food was available, the rats with extended access not only grew obese but also displayed “a progressively worsening deficit in neural reward responses.” The obese rats gradually developed an increased tolerance that required them to consume more and more food to achieve the same level of pleasure and satiety.
According to the authors, “These data demonstrate that overconsumption of palatable food triggers addiction-like neuroadaptive responses in brain reward circuits and drives the development of compulsive eating. Common hedonic mechanisms may therefore underlie obesity and drug addiction.” They also noted that their results could reflect on overweight individuals who “express a desire to limit their food consumption, yet struggle to control their intake and repeatedly consume beyond their energy requirements.” See Health.com, Scientific American, March 28, 2010; Time, April 3, 2010.
