The 21st century is currently witnessing a global shift and dominance within the health and fitness paradigm. The fitness and supplement industry has grown rapidly within the past ten years with more and more people investing in order to achieve optimum health and body image. However, is the growing popularity of such industries triggering pathways towards physiological food dependencies and addictions? The rapidly growing “trend” of diet and exercise that began as a way to increase the nation’s health, may be causing food addictions, sparking a global controversy that may have widespread implications within the food and drink industry. Recently, research has shown that strict diets and food deprivations, especially those of sugar and carbohydrates, common among industries such as the bodybuilding industry may be triggering food addictions. These food addictions are proposed to be based on brain neurochemistry, causing a series of behavioural changes that could be potentially leading to a series of eating disorders.

Sugar Addicition

It has been proposed that sugar is an addictive substance that stimulates the same brain pathways as heroin, this is based on observed behavioural and neurochemical similarities between the effects of discontinuous access to sugar and drugs of abuse. A well-known characteristic of addictive drugs is their ability to cause increases in extracellular dopamine (DA) in the nucleus accumbens (NAc). Food is not ordinarily like a substance of abuse, but it has been observed that intermittent bingeing and deprivation may change that. The Ingestion of different nutrients, such as fats and sugars, normally produces different effects on the brain and behaviour.  A deprivation of these nutrients, followed by consumption in the form of binges may lead to the release of excessive DA,  resulting in a series of behavioural changes that are comparable to those of drugs of abuse. Drug addiction is a chronically relapsing disorder that involves a compulsion to seek and take a drug, a loss of control in intake, and the emergence of a negative emotional state (e.g. dysphoria, anxiety, and irritability). Drug addiction involves elements of both impulsivity and compulsivity that form a cycle consisting of three stages: (1) ‘the binge’, (2) withdrawal, and (3) The ‘craving’. “Addiction” is a term used to imply both a physical and psychological dependence, a mental or cognitive problem based on the compulsive need for a habit-forming substance. Humans are born with a preference for a sweet taste whereby an irregular access to sugar can increase this preference and causing both a physical and psychological addiction. In physical addiction, the body adapts a tolerance to the substance being used, in this case sugar, and gradually requires increased amounts to reproduce the effects originally produced by smaller doses.  However, in psychological sugar addiction there are a series of very cognitive processes that are associated with the consumption of simple carbohydrates, involving declarative memories, explicit predictions for the potential future based on these memories, and a cognitive understanding of the relationships between potential actions of sugar consumption and future outcomes.

The Evidence

Avena et al. (2008), showed studies whereby rats with intermittent access to sugar drank in a binge-like manner that released DA in the NAc, like the classic effect of an addictive drug. The rats were deprived of food for twelve hours and then given a twelve hour access to food, whereby they could consume laboratory chow and a solution of sucrose and glucose. After being kept on this schedule of forced deprivation for a month, they found behavioural characteristics that were consistent to those observed with drugs of abuse, whereby the animals showed signs of addiction. During the first hour of access there was a large intake of sugar, the ‘binge’ stage; This was shortly followed by a sugar withdrawal, highlighted by a series of withdrawal symptoms, such as teeth chattering, forepaw tremor, and head shakes, as well as behavioural manifestations of anxiety. These signs of withdrawal shown in rats were found to be similar to those from drugs such as morphine, nicotine, and alcohol that are often accompanied by alterations in DA, an Extracellular DA decrease.

A Pathway to Eating Disorders?

However, unlike drugs of abuse, which exert their effects on DA release each time they are administered, the effect of eating palatable food on DA release does not exist unless the animal is food deprived. Observations by Avena et al, may have significant implications within the fitness and supplement industry and be important for understanding the bingeing behaviours associated with bulimia. Bulimic patients show a neurochemical imbalance of DA due to food restrictions and deprivation, therefore excess consumption of fats and sugars in the form of ‘binges’ may cause an addiction. David Benton (2010) supported this in his discussion on Binge-Eating Disorders (BED) in relation to sugar and food deprivation. He stated that BED is a recently recognised disorder, differing from bulimia nervosa whereby bingeing is not followed by vomiting, the use of laxatives or excessive exercise.  Binge Eating is characterised by the cycle of excessive overeating, often within a short period of time. This is usually followed by feelings of depression, guilt and disgust. Interestingly, this process has not only been shown to elicit these cognitive effects but the recent studies on lab rats supports that a physiological response can also be triggered where forced deprivation decreases DA levels, generating symptoms of withdrawal, this is known as “the deprivation effect”.

The Future Of A Fitter Society

What is beginning as a general fitness revolution has began to branch off into a range of different, more specialised industries. The supplement and body building industry is one of many, which has recently undergone rapid development with increasing investments. Personally, I am fascinated and would love to become a part of the body building industry, whereby the art of bodybuilding is one where the body can reflect strength, determination, hard work and overall fitness and wellbeing. However, is the industry producing mechanistic pathways towards exercise and eating disorders? A Bodybuilders’ main aim is to reduce fat and gain muscle, as a result, the foods consumed should aid the reduction of fat and increase lean muscle mass. Bodybuilding is therefore accompanied by a series of strict dieting regimes. A strict bodybuilder’s diet should avoid simple carbohydrates, processed foods, sugar and foods that have high sodium and high saturated fat contents. Therefore, the industry itself could be causing physical addictions to food, leading to a food compulsion and body image disorders. On the surface the societal fitness trend is increasing the nation’s general health and well being,  which may lead to a decrease in obesity for future society. However, controversy exists to whether the growth of the fitness industry is causing a series of food addictions and underlying disorders.

References

David Benton. (2010). The plausibility of sugar addiction and its role in obesity and eating disorders. Clinical Nutrition . 29 (3), p288–303. Nicole M. Avena, Pedro Rada, Bartley G. Hoebel. (2008). Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neuroscience and Biobehavioral Reviews. 32, p20–39. Nicole M. Avena. (2010). The study of food addiction using animal models of binge eating. Appetite . 55 (3), p734–737. Nicole M. Avena, Pedro Rada, and Bartley G. Hoebel. (2009). Sugar and Fat Bingeing Have Notable Differences in Addictive-like Behavior.The Journal of Nutrition. p623-628.

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