Food, glorious food? Obesity could stem from addiction - study

© David Gray
The popular assumption that obesity is simply the result of a lack of willpower could be contested by new international research. It posits that obese people's brains are predisposed to food addiction in much the same way a drug addict’s are to substance abuse.

It all has to do with different brain networks being activated in those suffering the condition and those who don’t.

Scientists with the European College of Neuropsychopharmacology (ECNP) believe new doors to obesity treatment could be open as humanity gains a better understanding of the cause of the problem.

It’s no wonder, say the researchers, that repeated attempts to manage the problem or cure it have been fruitless – apart from bariatric surgery. They believe treatment should address the addiction mechanisms that play a key role.

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The study encompassed 39 obese people and 42 with normal weight. A simple test was carried out: the groups were shown pictures of food, while their brain responses were gauged with equipment. The MRI results showed two distinct zones lighting up.

The center responsible for reward-based behavior – known as the dorsal caudate – would light up in obese people. Another center that responded was the somatosensory cortex – the area that is responsible for assessing the energy value of food. To the researchers, this strong connection indicated a desire for food with a high calorie count.

The situation was different in individuals with normal weight: the ventral putamen, which evaluates flavors, and the orbitofrontal cortex, responsible for decision-making, would light up.

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By then measuring the body-mass index (BMI), researchers arrived at the conclusion that 11 percent of the weight gain in obese individuals was due to this increased connectivity between the two areas.

"There is an ongoing controversy over whether obesity can be called a ‘food addiction,’ but in fact there is very little research which shows whether or not this might be true,” said lead researcher Oren Contreras-Rodriguez, of the University of Grenada, Spain.

“The findings in our study support the idea that the reward processing following food stimuli in obesity is associated with neural changes similar to those found in substance addiction,” Contreras-Rodríguez said.

“This still needs to be viewed as an association between food-craving behavior and brain changes, rather than one necessarily causing the other. However, these findings provide potential brain biomarkers which we can use to help manage obesity, for example through pharmacotherapies and brain stimulation techniques that might help control food intake in clinical situations."

The research was carried out in cooperation with the Monash University in Australia.