People can become addicted to eating for its own sake but not to consuming specific foods such as those high in sugar or fat, research suggests.
An international team of scientists has found no strong evidence for people being addicted to the chemical substances in certain foods.
The brain does not respond to nutrients in the same way as it does to addictive drugs such as heroin or cocaine, the researchers say.
Instead, people can develop a psychological compulsion to eat, driven by the positive feelings that the brain associates with eating.
This is a behavioural disorder and could be categorised alongside conditions such as gambling addiction, say scientists at the University of Edinburgh.
They add that the focus on tackling the problem of obesity should be moved from food itself towards the individual's relationship with eating.
The study, which examined the scientific evidence for food addiction as a substance-based addiction, is published in Neuroscience & Biobehavioral Reviews.
The researchers also say that the current classification of mental disorders, which does not permit a formal diagnosis of eating addiction, could be redrawn. However, more research would be needed to define a diagnosis, the scientists add.
The work was carried at the Universities of Edinburgh, Aberdeen, Gothenburg, Essen, Utrecht and Santiago de Compostela.
The researchers are involved in the NeuroFAST consortium, which is an EU-funded project studying the neurobiology of eating behaviour, addiction and stress.
Dr John Menzies, Research Fellow in the University of Edinburgh's Centre for Integrative Physiology, said: "People try to find rational explanations for being over-weight and it is easy to blame food.
"Certain individuals do have an addictive-like relationship with particular foods and they can over-eat despite knowing the risks to their health. More avenues for treatment may open up if we think about this condition as a behavioural addiction rather than a substance-based addiction."
Professor Suzanne Dickson, of the University of Gothenburg and co-ordinator of the NeuroFAST project, added: "There has been a major debate over whether sugar is addictive. There is currently very little evidence to support the idea that any ingredient, food item, additive or combination of ingredients has addictive properties."
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