Obese people may be afflicted with 'food addiction'

The tendency to want food may be 'hard-wired' into the brain of overweight people, says a new study that supports the theory that brain mechanisms underlying obesity may be similar to those in substance addiction.

The researchers found that food craving activates different brain networks between obese and normal weight patients.

"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 from University of Granada in 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-Rodriguez noted.

The study looked for the functional connectivity differences in brain reward systems of normal-weight and obese individuals.

The researchers gave buffet-style food to 39 obese and 42 normal-weight individuals.

Later, they were put into functional MRI brain scanners and shown photographs of the food to stimulate food craving.

The functional MRI scans showed that food craving was associated with different brain connectivity, depending on whether the participant was normal-weight or overweight.

They found that unlike in normal weight people, in obese individuals, the stimulus from food craving was associated with a greater connectivity between the dorsal caudate and the somatosensory cortex, implicated in reward-based habits and the coding of the energetic value of foods, respectively.

The researchers then measured body mass index (BMI) three months afterwards and found that 11 percent of the weight gain in the obese individuals could be predicted by the presence of the increased connectivity between these two areas of the brain.

The findings were presented at the European College of Neuropsychopharmacology's annual meeting in Amsterdam, the Netherlands.