FOOD is often seen as a comfort. Chocolate has long been associated with evoking the feel-good-factor but now, it seems, our behaviour with food may be more psychological than we thought.

An international team of scientists has found no strong evidence that particular chemical substances in foods are addictive. The brain doesn't respond to nutrients in the same way as it does to addictive drugs like heroin or cocaine.

It is the positive feelings that our brains associate with eating that makes some people develop a psychological compulsion to consume, research has found.

This is a behavioural disorder akin to conditions such as gambling addiction, scientists said, and any measures to tackle the problem of obesity should focus on the individual's relationship with eating and move away from the food itself.

The study, which examined the evidence for over-eating as a substance-based addiction, was carried out by the universities of Edinburgh and Aberdeen and scientists in Sweden, Germany, the Netherlands and Spain and is published in the journal 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, the scientists said that more research would be needed to define a diagnosis.

Dr John Menzies, research fellow at Edinburgh University's Centre for Integrative Physiology, says: "People try to find rational explanations for being overweight 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 from Gothenburg University, adds: "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 ingredient has addictive properties."

The researchers are all involved in the NeuroFAST consortium, a project studying the neurobiology of eating behaviour, addiction and stress.

Verner Wheelock, a former Bradford University professor and microbiologist who founded the Food Policy Research Unit advising the food and farming industries on healthy eating and now runs Verner Wheelock Associates, an award-winning consultancy providing expert training to the food industry based in Skipton says what we put in our mouths rather than the amount is far more important.

"All the evidence now that we need low carb and high fat is getting stronger by the day," says Verner.

"We need to look much more carefully at what happens to the different components of the diet. "

While some may frown on bacon and eggs for breakfast due to the fat content of the meal, Verner argues that it is actually more filling than high sugar cereals which often leave people craving for something else to eat before dinner-time.

"You don't worry about calories it is the carbohydrates you need to worry about," says Verner.

Sugar is also a concern, according to Verner. "There are some people who will say sugar is addictive but it does not satisfy you, to my mind. It may not be addictive but if it is not meeting their requirements you are still hungry."

He says some people may get a certain amount of short term satisfaction from consuming a diet which is high in sugar and refined carbohydrates.

But Verner advises: "You need to stand back and look at the bigger picture."

Professor Paul Gately, director of MoreLife which has been running weight management residential camps in Bradford, says: "As past research on food and its addictive qualities has been poor, this is a welcome study. When working with overweight people, it is important to understand the factors that contribute to weight gain, only then can we design effective weight loss programmes. Although further research into the addictive qualities of food is necessary, this study validates the cautious approach we take when designing our evidence-led interventions.”

Dr Ellie Bryant, lecturer in psychology at the University of Bradford, agrees with the study's findings and believes the 'reward' people get from food is addictive rather than the ingredients themselves.

"People use food for all sorts of things. They use food to cope when feeling down and stressed - it is the effect food has on the brain."

Ellie believes people often rely on a food as a 'quick fix.' "People become reliant on high fat and sweet foods to make them feel better rather than doing exercise or talking it out with a friend or dealing with it in another way," she says, referring to the fact that people often find it easier reaching for a bar of chocolate or a bag of crisps.

She says instead of changing their eating behaviour they need to focus on the reasons behind why they use foods to self-medicate. "If people realise they are self-medicating and using food to make themselves feel better people it is easier to tackle that behaviour and change it, " says Dr Bryant.

Bradford is one of seven cities in Europe participating in a healthy eating project. Launched today, 'We Love Eating' aims to promote healthy eating and exercise through a number of initiatives to improve people's during the year.

The Bradford project involves organisations including Born in Bradford, Shipley's HALE (Health Action Local Engagement), Jamie's Ministry of Food and Forster College, both in Bradford.