The special issue of Biological Psychiatry takes a deeper look at the questions surrounding the idea of food as an addiction - with research reviews covering the possible neurobiological mechanisms and characteristics of food and substances of abuse.
Led by guest editors Dr Dana Small and Dr Ralph DiLeone, both from the Yale School of Medicine, USA, the special edition brings together original research findings, systematic reviews and opinions of key leaders in the field to objectively represent the state of the field and both sides of the debate.
"While it is attractive to use the addiction framework to 'jump start' and guide our understanding of how neural circuits of reward and self-control might contribute to understanding overeating and the obesity epidemic, the price of adopting an inappropriate framework would be high," said Small and DiLeone.
"For example, an inappropriate adaptation might steer research towards evaluating variables that have been shown to be critical for addiction at the expense of those that are unique to obesity and perhaps key to understanding overeating."
Addiction is defined as a continued or compulsive use of a substance, despite negative and/or harmful consequences. However, over the years, addiction has come to be re-defined to include behaviours, as well as substances, and the term is now used to describe significant problems with alcohol, nicotine, drugs, gambling, internet use, and sex.
These 'major' addictions, like alcoholism and drug abuse, stimulate significant amounts of research and are now largely well characterised, but others, like pathological gambling and internet addiction, are much less understood.
Then there is food – which is a biological necessity. It is this distinction that makes it unlike any of the other substances or behaviours typically considered as addictive, noted Small and DiLeone – adding that the concept of a food addition therefore doesn't qualify when considering typical conditions of abnormal dependence upon a substance – such as tolerance or withdrawal.
However, research has long found similarities between food intake and addiction.
The special edition – found in full here – tackles the lack of clarity in the scientific literature by providing a cohesive look at the support for and against the application of the addiction model to food.
One review, led by Dana Smith from the University of Cambridge, UK, provides a rationale for adopting the food addiction model; arguing that food addiction exists and that although food is less powerful than addictive drugs, this does not diminish the compulsive nature or lack of control associated with binge eating.
In contrast, a separate paper led by Professor John Salamone from the University of Connecticut, USA, contends that the concept of food addiction is problematic and its links to drug addiction are overstated – adding that there is much more research needed in the area
These contrasted papers are followed by reviews and research papers covering topics including brain reward circuitry, obesity and dopamine, impulsivity and self-control, reward-driven feeding, and the effects of a high-fat diet.
The contributing experts also attempt to provide comment on the future directions for additional research and policy implications – such as how it may inform debates on how to address issues of diet, nutrition and obesity prevention.
“If certain foods do have an addictive potential but this reality is ignored, it is likely that both treatment and policy progress will be stalled,” warns Dr Ashley Gearhardt from the University of Michigan, USA, in commentary.
“It is essential to evaluate whether certain foods have addictive potential, but much more will be required to translate this science into game-changing realities, changes in the national discourse about food, and in decisions made by policy makers,” Gearhardt and her colleagues add.