Brain changes in chocoholics that occur when they see or eat chocolate are similar to those in addicts when they take drugs, scientists say.
British researchers found certain regions of the brain were more active when people who confessed to cravings were fed or shown pictures of chocolate than in non-cravers.
They also discovered the sight of chocolate contributed significantly to the activation of brain areas associated with reward - suggesting that dieters could cut their intake by avoiding the sight of foods they particularly desire.
Prof Edmund Rolls and Ciara McCabe at the University of Oxford's experimental psychology department carried out functional magnetic resonance (fMRI) imaging on the brains of eight chocoholics and eight non-cravers. All participants were women.
The volunteers were shown appetising pictures of chocolate and then fed liquid chocolate while having fMRI scans.
Among chocolate cravers, greater activity was seen in the medial orbitofrontal cortex, pregenual cingulated cortex and ventral striatum - regions of the brain known to be involved in pleasure sensation, habit-forming behaviours and drug addiction.
Damage to the orbitofrontal cortex acquired through brain injury has previously been associated with compulsive gambling and excessive use of alcohol and drugs.
The fMRI scans also demonstrated the combination of the sight and taste of chocolate produced a stronger response in both cravers and non-cravers, than either separately.
Prof Rolls, whose findings were published in the European Journal of Neuroscience, said: "Understanding individual differences in brain responses to very pleasant foods helps in the understanding of the mechanisms that drive the liking for specific foods and thus intake of those foods.
"Sight and flavour combined give a much bigger response than seeing or tasting the food separately. The sight component is important and complements the flavour.
"If you want to limit [food] intake, you could limit the extent to which you are exposed to the combination of sight and taste. For example, you could eat in the dark."
Prof Rolls said eating a desired food without seeing it was a parallel experience to eating food when you cannot smell it because of having a blocked nose.
He added: "To our knowledge this is the first study to show that there are differences between cravers and non-cravers in their responses to the sensory components of a craved food in the orbitofrontal cortex, ventral striatum and pregenual cingulate cortex."