A very common misconception among patients and their families is that adults who suffer from Binge Eating Disorder just “lack self-control” or are “greedy” when it comes to food. These ideas couldn’t be more wrong, and it is very important that patients with a Binge Eating Disorder diagnosis are reassured that their situation is caused by a medical disorder, and not a moral or personal failing, so that they may recognize that their condition is treatable. In this blog, we will explore possible eating disorder causes.
The exact cause of Binge Eating Disorder is unknown, and it’s possible there is more than one cause. However, a considerable and growing body of research points to a neurobiological dysfunction as the source of Binge Eating Disorder. While we don’t yet have enough information to form a complete, definitive picture of how the disorder( s) work, current knowledge has led to several theories. Each theory relates to a specific behavioral pathway— reward processing— but they take slightly different approaches as to where the pathway deviates from the healthy function seen in people without eating disorders. Let’s explore the possible binge eating disorder causes below.
Impulse–Reward Dysfunction
The first hypothesis is that Binge Eating Disorder relates to decreased activity in the impulse control–related areas of the brain as well as increased activity of the brain’s reward centers. Put another way, the neurons in the parts of the brain that govern impulse control simply don’t react as much as they should in people with Binge Eating Disorder, so the ability to exert control over eating behaviors that trigger the reward response is decreased or lost entirely. At the same time, the reward associated with eating is experienced more intensely.
The first possible Binge Eating Disorder cause is Impulse – Reward Dysfunction. This hypothesis has been supported by studies that used functional magnetic resonance imaging (fMRI) to image the brains of volunteers, some with Binge Eating Disorder and others without Binge Eating Disorder, to compare how their brain activity differed when they viewed images of food as well as other, more neutral images. The studies noted differences between participants without eating disorders and those with eating disorders in both the limbic and paralimbic areas associated with reward processes as well as in the prefrontal areas supporting cognitive control processes. Let’s continue exploring more possible binge eating disorder causes.
Neurotransmitter Dysregulation
Neurotransmitter Dysregulation is another possible binge eating disorder cause. A second, related hypothesis zeroes in on a specific neurotransmitter that is a key participant in the brain’s reward system: dopamine. 29 In general terms, dopamine is the neurotransmitter that bridges the gap between the neurons of the prefrontal cortex (which participates in cognitive functioning around emotions and behavior) and the neurons of the nucleus accumbens, the part of the brain associated with pleasure and impulsivity. Dopamine dysregulation can create an intense sensation of “wanting” food— not necessarily a specific food, but just food in general. More specifically, dopamine binds to two receptors, the D2 and D4 receptors, which have been found to have an association with binge eating. Studies that look at the variations in the genes that encode the D2 receptor, for example, found that individuals with Binge Eating Disorder often had specific genotypes that enhance the “reward” experience of dopamine.
Dysregulation of Endogenous Mu-Opioid Signaling
A third hypothesis points to another pathway in reward processing: the endogenous opioid signaling pathway. Endogenous opioids— dynorphins, enkephalins, endorphins, endomorphins, and nociceptin— convert sensory stimuli into processes that generate or enhance the “liking” of a particular food. 33,34 Specific receptors called mu-opioid receptors are abundant within the spinal cord, intestinal tract, and brain; they are present on neurons throughout the nucleus accumbens. These receptors allow endogenous opioids to create additional “reward” signals independent of dopamine; individuals with Binge Eating Disorder may have increased mu-opioid receptor binding, producing both an increased “liking” for a specific food as well as a feeling of pleasure from that food, which in turn leads to short episodes of binge eating on that food. It probably should come as no surprise that many of the foods that commonly trigger binge eating are nutrient-dense— that is, high in carbohydrates or fats.
It is interesting to note that while each of these hypotheses has supporting evidence for how it could contribute to Binge Eating Disorder, there is no reason to believe that any specific patient might not have a combination of two factors, or even all three, happening at the same time. At the moment, we simply do not know enough about the mechanisms of Binge Eating Disorder to say for sure which factor or factors are most important.
Despite the limitations of our current knowledge, there are some common risk factors to consider.
Family History
Binge Eating Disorder runs in families and twin studies have shown that genetic factors play a role. Specific genes that influence risk for Binge Eating Disorder have not yet been identified although research is underway. Also, an association between Binge Eating Disorder and depression in the patient’s parents was found in some studies.
Social factors. Individuals subject to frequent, long-lasting negative commentary regarding their weight or body shape, either via parental/ spousal criticism or discriminatory/ bullying behaviors by peers, may be at increased risk of Binge Eating Disorder. A history of irregular or restrictive eating patterns, frequent weight changes or “yo-yo dieting” may be present.
Adverse or traumatic events. Experience of particularly stressful events or situations, such as a natural disaster or life-threatening accidents, has been found to be associated with Binge Eating Disorder. Alternatively, a history of abuse, neglect, sexual assault, or similar psychosocial trauma may be present.
Dieting. Some research has indicated a link between extreme dieting and disordered eating, with binge eating beginning when individuals let go of rigid eating strategies. Extreme dieting differs from moderate forms of dieting and may include strategies such as delaying eating (for example, not eating during the day), severely restricting overall calorie intake, and completely forbidding certain foods, such as carbohydrates, fats, sugars, etc. One hypothesis is that the body experiences extreme dieting as being similar to starvation and reacts by preparing to eat large amounts of food in short periods of time. This creates a vicious circle in which periods of binge eating and severe calorie restriction continually follow one another.
Mental health comorbidities. It is common for Binge Eating Disorder patients to have additional diagnosed or undiagnosed mental health issues, including addiction, anxiety, bipolar disorder, depression, or other mood disorders.
These hypotheses are possible Binge Eating Disorder causes. Do you have any questions or additional possible Binge Eating Disorder causes? Leave a comment!