Food Addiction

Eating types and amounts of foods that seem to contrast with a person’s intentions to make moderate and ‘sensible’ food choices, has been described as food addiction. Do we know what drives people to make certain food choices that appear to be the opposite of their stated intentions? Can consistently eating the wrong foods really be described as an addiction? Or is this just the battle between the growling stomach and the cerebrum (the conscious part of the brain).

Addiction is a term that covers many human behaviours, and describes a recurring compulsion to do something that is difficult to discontinue. The term is usually used for behaviours with substances that are psychoactive, and that can cross the blood-brain barrier to directly stimulate the brain (alcohol, tobacco and various drugs). The classic pharmacologic use of the term addiction also includes the concept of ‘tolerance’, which is the requirement for greater doses of a substance used over time, to achieve the same effects. Addiction is sometimes also used in an extended way to describe other ‘adverse’ behaviours such as gambling, inappropriate shopping or computer use. Whether compulsive or bizarre eating practices are due to specific effects of foods on brain chemistry or due more to psychological dependencies, is difficult to assess.

Some researchers claim that there are common neurobiological features in drug addiction and binge eating. Large amounts of the neurotransmitter dopamine are released in the brain (the nucleus accumbens) when we experience pleasure, and the use of cocaine and amphetamines also stimulates this reaction. This reward system also affects a part of the brain that regulates eating behaviour, the hypothalamus.

Research with overweight volunteers at the National Institute on Drug Abuse in the US have been able to demonstrate a pattern of fewer dopamine receptors in parts of the brain with increasing obesity. Their hypothesis is that some overweight individuals may have a dopamine shortage, causing them to constantly seek stimulus in the form of food: their brains then compensate for the dopamine overproduction that then occurs, by reducing the number of dopamine receptors.

The brain processes the stimuli related to eating in a similar way to other addictive stimuli, and it may be that in some individuals these are different, resulting in stronger drives to consume different amounts or types of foods. Researchers are investigating whether some medications originally developed to treat drug addicts may also be able to help overeating behaviours.

Some researchers, however, are sceptical that difficult food behaviour should be described in the terms used to define other ‘addictions’. Instead, food cravings should be considered within the normal variations of appetite control merging with the psychological processes of control and restraint within the social and cultural markers of appropriate intakes of foods.

While exercise and healthy eating habits are the well-proven routes to good health in nearly all people, current research from neuroscience may help dietitians to better support people who find their eating habits at odds with their intentions. However ‘breaking the cycle’ needs to start with eating enough of the foods known to promote good health.

This information was correct at issue. For personal dietary information, a local dietitian is the best source of information. Want to be sure the dietitian you consult is registered? Check the Health Professions Council search facility of dietitians registered in the UK (www.hpc-uk.org)

Issue date: June 2007