Compulsive eating, drug addiction driven by same mechanism


Washington : The same molecular mechanisms that drive people into drug addiction are behind the compulsion to overeat, says the latest research.

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The new study was conducted by Paul J. Kenny, professor at Scripps Research’s Florida campus and graduate student Paul M. Johnson.

The study shows clearly that in rat models, the development of obesity coincides with a progressively deteriorating chemical balance in reward brain circuitries.

Kenny said that the study, which took nearly three years to complete, confirms the “addictive” properties of junk food.

“The new study, unlike our preliminary abstract, explains what happens in the brain of these animals when they have easy access to high- calorie, high-fat food,” said Kenny.

“It presents the most thorough and compelling evidence that drug addiction and obesity are based on the same underlying neurobiological mechanisms. In the study, the animals completely lost control over their eating behaviour, the primary hallmark of addiction,” added Kenny.

“They continued to overeat even when they anticipated receiving electric shocks, highlighting just how motivated they were to consume the palatable food.”

The scientists fed the rats a diet modelled after the type that contributes to human obesity-easy-to-obtain high-calorie, high-fat foods like sausage, bacon, and cheesecake. Soon after the experiments began, the animals began to bulk up dramatically.

“They always went for the worst types of food,” Kenny said, “and as a result, they took in twice the calories as the control rats. When we removed
the junk food and tried to put them on a nutritious diet – what we called the ‘salad bar option’ – they simply refused to eat.”

“The change in their diet preference was so great that they basically starved themselves for two weeks after they were cut off from junk food,” said Kenny.

These findings were published in the Sunday online edition of Nature Neuroscience.