In a Clinical Nutrition course I'm taking, there was a recent message board topic related to eating disorders.
A recent article in the Las Vegas Review Journal discussed Binge Eating Disorder (BED) at length, and how it's the most common eating disorder and is poised to get it's own classification in the DSM-V, to be released in 2013.
For the assignment, students were to read the article, then answer the following questions:
1. Is BED and addiction just like drugs or alcohol? Why or why not?
2. Should BED, anorexia, and bulimia be treated as psychological conditions, medical conditions, or both?
3. Is it good or bad for BED to be classified as its own specific eating disorder in the DSM-V?
4. Do you believe eating disorders and body image issues can be a learned behavior?
I'll share my thoughts below:
1. Binge Eating Disorder (BED) most likely manifests itself as an addiction, like drugs or alcohol, because the food typically (or what I would imagine to be typical) consumed during a binge is going to light up the same pathways that a drug would, notably the nucleus accumbens, the ventral tegmental area, and the dopamine reward circuitry.
Foods such as sugar have been shown to affect the reward system in much the same way as drugs. There was a recent study in rats that showed the subjects were more likely to choose intense sweeteners over cocaine:
In 2007, researchers at the University of Bordeaux, France, reported that when rats were allowed to choose between a calorie-free sweetener and intravenous cocaine, 94 percent preferred the sugar substitute. The researchers concluded that "intense sweetness can surpass cocaine reward. . . . The supranormal stimulation of these receptors by sugar-rich diets, such as those now widely available in modern societies, would generate a supranormal reward signal in the brain, with the potential to override self-control mechanisms and thus to lead to addiction." Nicole Avena, an expert in behavioral neuroscience at the University of Florida in Gainesville, has spent many hours analyzing the behavior of rats enticed into sucking up sugar. She says that feeding on sugar can, like snorting coke, lead to bingeing, withdrawal, and craving. It does this by lighting up the same circuitry within the brain triggered by cocaine and amphetamines, the dopamine center.
(Maybe they were just strapped for cash?)
At Princeton University, Bart Hoebel has been studying the effects of sugar on behavior and the reward circuitry:
Hoebel has shown that rats eating large amounts of sugar when hungry, a phenomenon he describes as sugar-bingeing, undergo neurochemical changes in the brain that appear to mimic those produced by substances of abuse, including cocaine, morphine and nicotine. Sugar induces behavioral changes, too. "In certain models, sugar-bingeing causes long-lasting effects in the brain and increases the inclination to take other drugs of abuse, such as alcohol," Hoebel said.(His group also found that high-fructose corn syrup was particularly egregious in the development of excessive body fat in rats.)
I believe that BED works in much the same way. Many binges probably include sugar, or excessive carbohydrate consumption which would virtually mimic or perhaps surpass the effects of a sugar binge in terms of an addictive response to the experience, setting up a pattern for a vicious cycle of reward and withdrawal which has physiological underpinnings with blood glucose, insulin, and the reward pathways.
2. I think that many cases of BED manifest themselves as psychological problems, but have physiological underpinnings, as discussed in answer #1. In other words, the physiology is going to drive the psychology. A couple of examples from the slides on eating disorders informed us that anorexia is more associated with type 1 diabetes and bulimia with type 2.
This makes sense physiologically, not psychologically. Someone who is type 1 diabetic, generally cannot produce insulin, which is the primary regulator of fat storage. Type 1 patients are going to appear anorexic and anorexic patients are going to appear type 1 diabetic.
For type 2 diabetics, we oftentimes have the issue of hyperinsulinemia. We’re overproducing insulin, which leads to excessive fat accumulation, but the kicker is that this patient is starving as much as the type 1 diabetic. They are losing energy to their fat tissue and therefore it cannot be utilized by the cells of the body or for normal metabolism. It’s as if they have a leak, except the leak is not exogenous, rather it travels to the adipose tissue, and when you look at someone who is morbidly obese, it’s a sign that they are, in effect, starving internally.
In this context I think BED is a medical or physiological condition, which includes an addiction to the cycle, and I also think that a Rehab or behavioral clinic can be helpful for patients, so I consider there to be both medical and psychological factors, however it’s ultimately the physiology driving the behavior.
3. I think it’s good for BED to be classified as its own eating disorder so that it can be isolated and treated. I do tend to think that BED and bulimia nervosa (BN) are virtually synonymous. In that respect, I feel like the diagnosis of BED as its separate condition is useful in demonstrating how prevalent binge eating is, which includes both bulimia and BED. I would imagine that, just like the case with Ms. Turner in the article, that there is a cycle of binging and restriction with BED. Granted, with BED, there may not be overt purging behavior, but Ms. Turner reportedly began to restrict her intake, “which would inevitably lead to another episode of binge eating.” That sounds like BN to me.
4. Eating disorders and body image issues can be a learned behavior, but they are retained because of our underlying physiology, and some people will have a greater propensity to develop a disorder through their own biology, genetics, biochemistry, and physiology.
For example, if one were a relatively lean individual and never had to diet a day in his life, but he remained skinny, would he develop an eating disorder? I think it would be much less likely than someone who constantly struggles with their weight. For this person, they will be more likely to binge and purge as a repeated cycle in the insatiable desire to be thin (purge or restriction) and the virtually unstoppable biological compensatory mechanisms coupled with addictive underpinnings that will inevitably lead to “excessive” energy intake (binge or increased consumption).
And if someone who is diagnosed with BN, but is otherwise relatively lean, say they are chronic exercisers and eat meals over 1000 kcals, how can we truly say that they are eating “excessively?” Technically, they’re not overeating if they’re not overweight.
I think that for most people who are actively trying to lose weight by consciously counting calories, almost by definition, have an eating disorder. They are engaging in purgative behavior, whether it’s consciously restricting calories, or consciously increasing energy expenditure through exercise, but this is what we prescribe to individuals. And if they still remain overweight, then, by definition, they’re overeating. This is why I think the term overeating is a misnomer.
In this sense, while I think type 2 diabetes is a pathological medical condition, it can be a learned behavior in the respect that if I grew up in a household where I was fed daily a menu consisting of frosted flakes, skim milk, orange juice, a banana, and wheat toast for breakfast; skim milk, sun chips, an apple, potato chips, and bread for lunch; pasta with marinara, green beans, bread, a soda, and a “grain-based dessert” (the number one source of calories for all age groups according to the 2010 Dietary Guidelines) for dinner, and I developed diabetes, did I learn this from my family and the health authorities? It didn’t help.
I think body image is a learned behavior in some respects. We see people leaner than us and we want to emulate them, which can lead to behavioral disorders, but it then gets tangled in the web of physiological factors as well.