When we hear the term “eating disorder,” we often think of the woman at our gym who looks unhealthily thin or maybe a friend who meticulously monitors each calorie he or she consumes. Though anorexia nervosa (marked by low weight and a strong fear of weight gain) is a serious and harmful mental illness with one of the highest mortality rates of any psychiatric illness, the reality is that the most common eating disorders are bulimia nervosa and binge eating disorder, both of which involve—and in fact, require for their diagnoses—binge eating. Binge eating is defined as frequent episodes of eating more than most people would consider normal during a discrete period of time. Thus, although our stock mental image of an eating disorder is usually characterized by severe undereating, many individuals with eating disorders actually struggle with patterns of overeating. In fact, most people don’t know that there is a subtype of patients with anorexia nervosa who also struggle with binge eating.
What types of food do people tend to binge on? According to a research study, both obese women with binge eating disorder and those without binge eating disorder consumed more snack and dessert foods (e.g., ice cream, cake, and potato chips) during a “binge” meal when they were instructed to “let yourself go and eat as much as you can,” indicating that these are the types of food items that people tend to overindulge in when given the opportunity. Another study analyzing the food content of binge episodes among women with bulimia nervosa also found that binge meals include more snack and dessert items.
For the past decade or so, my laboratory has been interested in studying how consumption of highly palatable—or tasty—ingredients, especially sugar and fat, affects the brain reward system, with a particular focus on their effects on dopamine. In a series of studies using laboratory animal models, we have looked at this question from many different angles. For instance, we have investigated how sugar consumption affects dopamine release when rats are underweight as well as how eating a cafeteria diet—composed of many different food items including cheese, marshmallows, and chocolate chip cookies to model the variety available in our current food environment—affects dopamine release in obese rats. The overall take-away from these studies is that palatable food consumption leads to heightened dopamine release, which may help to explain why we tend to indulge in or overeat these foods in particular and continue to eat them despite knowing the harm they can have on our bodies.
While my laboratory’s work has primarily focused on the neural response to palatable food, our eating habits are shaped by a myriad of powerful factors, including taste, cost, cultural traditions, social and other visual cues, convenience, as well as smell (recall the last time you passed a Cinnabon shop in the mall!). Unfortunately, many of these factors collide to make palatable food options appealing on several levels. These foods tend to be tasty, low cost, conveniently packaged for eating on the go, marketed heavily, involved in many of our social and cultural celebrations, and can smell delicious. This helps to explain why overconsuming palatable food is not only a problem for those struggling with certain eating disorders but for society on a larger level and may contribute to the staggering rates of overweight and obesity in the United States today.
Special thanks to Ms. Susan Murray for her assistance with drafting this blog post.
Image Credit: “Cake Pops” by White77. Public Domain via Pixabay.