Claims that people can get ‘hooked’ on certain foods which then makes them obese are overstated, with the result that food addiction is becoming an overly simplistic explanation for overeating, according to a leading expert in psychobiology.
While it is possible that a very small percentage of the population – about 5% – could be ‘food addicts’, the idea of food addiction is exaggerated, said professor John Blundell, who holds a chair in psychobiology at the Institute of Psychological Sciences at the University of Leeds.
“The term food addiction is being used too freely as an explanation for overeating,” said Blundell. “The condition has been described in the clinical literature for decades; only recently has the term food addiction been applied on a much larger scale to implicate millions of people and to be compared with drug addiction.”
Blundell will be chairing a conference ‘Food Addiction – what is the evidence?’ being held today [Monday October 7] in London. The event is being organised by the British Nutrition Foundation (BNF).
Academics speaking at the conference will discuss the latest scientific evidence behind the concept of addiction in relation to food.
“As a term, food addiction is confusing and sometimes contradictory,” added Blundell. “The evidence for the concept comes from a combination of experimental data, anecdotal observations, scientific claims, personal opinions, deductions and beliefs.
“It is a simplification of a very complex set of behaviours and is now being connected with obesity, with the suggestion that it is a clinical explanation for the epidemic.”
88% of consumers believe sweet foods are addictive
A recent survey conducted by the BNF showed that 88% of consumers believe that sweet-tasting foods are addictive.
Sara Stanner, BNF nutrition science programme manager, said: “Humans have an innate desire for sweet tasting and energy-dense foods from birth, so it’s not surprising that some people think that their cravings for specific foods are driven by a physiological need.
“But there are many other factors influencing our desire for these types of foods, not least the learning mechanisms that encourage us to turn to certain foods linked with various emotions as a habit.”
Also addressing the conference, Peter Rogers, professor of biological psychology at the University of Bristol, said: “People use attributions to explain their behaviour. So, for example, the idea that they might be addicted to a particular food may lead them to believe that they have been ‘taken over’ by that particular substance and that their behaviour is, therefore, out of their control.
Removing personal responsibility
“The implication of this is that overeating is not their fault and they can’t help it. Removing personal responsibility for overeating is both attractive to the individual and potentially counterproductive to change.”
Ian Macdonald, professor of metabolic physiology, Faculty of Medicine and Health Sciences at the University of Nottingham and member of the Scientific Advisory Committee on Nutrition, will consider the evidence that fructose and sucrose may have specific effects on our metabolism or central nervous system that could equate with the effects of proven addictive substances such as cocaine.
Macdonald said: “Addiction is a specific clinical definition with human behaviours related to it. It has been claimed that the sweetness of sucrose, and particularly fructose, leads to behavioural changes which resemble addiction.”
Carbohydrates not addictive like drugs
However, he added: “Carbohydrates are nutrients which provide energy that the body needs and therefore they cannot be classified as addictive in the way that drugs are.
“The confusion around foods and addiction comes partly from functional imaging research which shows that the brain’s reward areas are stimulated by sweet foods. However, these areas of the brain are also stimulated by a lack of sugar and no one has suggested that a lack of sugar is addictive.”
Macdonald went on to explain that the brain is totally dependent on a continuous supply of glucose in order to function normally. “This is a basic survival function and it is not surprising therefore that reward centres are activated by such foods,” he added.
“Also, contrary to popular belief, sugar itself eaten in excess is not bad for you, only when it’s eaten in a diet that includes more energy than your body needs. There is also no strong evidence that fructose is worse for you than glucose or that either is damaging to health in terms of metabolism.”