Interviewed by Mark Gold, MD
FEATURED ADDICTION EXPERT:
Ashley Gearhardt, PhD
Assistant Professor of Clinical Psychology, University of Michigan
Can you describe organization rationale and outcomes of the “historic” Yale Conference?
The Yale Conference on Food Addiction was the first gathering of experts across the fields of addiction, obesity, and feeding behavior to focus on the question of whether certain foods can be addictive. The presentations and conferences that took place over the course of that meeting influenced much of the foundational thought about how addictive processes may be contributing to overeating and supported the emergence of this new area of study.
How do you describe food addiction in 10 words or less? How is it different than sugar addiction?
Compulsive overeating triggered by repeated exposure to highly rewarding food. While I see (added) sugars as one of the most relevant ingredients to addictive-like eating, other ingredients also appear to be implicated. For example, potato chips and French fries are commonly eaten in an addictive-like way, but they have a low sugar content. They do have a higher starch content (which is converted to sugar in the body) and fat content. The food addiction term broadens the scope of focus beyond sugar.
At the time that we first started doing this work, there was no scale to measure food addiction. Researchers were using obesity as a proxy, which we had some concerns about. Obesity can be caused by so many factors (e.g., medication side effects, genetic conditions, physical inactivity), using it as a marker of an addiction to food is not super precise. We also saw that some people who had body weights in the normal range were reporting addictive-like eating, but this was not reflected in their weight because of dieting practices, physical activity or a fast metabolism.
Other approaches out there were the use of self-identification (ex. are you a chocoholic?), but it was hard to know what this might be capturing. So, we decided to use the diagnostic criteria for substance dependence (and now substance use disorders based on the DSM 5) and translate it to apply to the consumption of highly rewarding foods (e.g., chocolate, salty snacks). This allowed us to use the same criteria that we would use to diagnose any other substance use disorder to measure addictive-like eating.
It was also important for us to specify the types of foods that were most likely implicated in food addiction. We all have to eat, but the type of eating behavior associated with food addiction is driven not by a need for sustenance, but to experience pleasure or to fulfill a craving. Our future work has further borne out that this is not an addiction to the act of eating, but more specifically to the intake of foods that have artificially high levels of rewarding ingredients (like refined carbohydrates and fat). As time goes on and more research comes out, I think one of the next steps will be revising the term of food addiction to more accurately reflect the types of food that are capable of triggering an addictive process. Perhaps, highly processed food addiction?
For clinicians evaluating disordered eating, it would be useful to assess for food addiction by including some version of the YFAS. We have developed and validated brief versions of the scale (see the modified Yale Food Addiction Scale 2.0) that can be used to quickly screen for an addictive-like phenotype. Food addiction and eating disorders appear to be overlapping, but distinct constructs with about half of individuals with an eating disorder meeting for food addiction. Individuals with both eating disorders and food addiction appear to have a more severe variant of the disorder. For example, in binge eating disorder, those with food addiction exhibit more frequent binge eating episodes, more emotion dysregulation, and greater impulsivity. In bulimia nervosa, higher levels of food addiction symptoms at baseline predict worse treatment outcomes in response to a brief psychosocial treatment. Thus, knowing if an eating disorder patient has also high YFAS scores may inform clinical care. It is also important to note that about half of people with food addiction do not meet the requirements for an existing eating disorder. So, the use of the YFAS may also help understand the eating problems of people who do not clearly fit into traditional eating disorder categories. We also see that rates of food addiction are elevated for individuals with depression and post traumatic stress disorder, so it may also be important to assess in more general mental health clinics.
The overlap between binge eating disorder and food addiction really is not that surprising when we step back and look at these conditions from a mechanistic level. Both binge eating disorder and addiction perspectives theorize that dysfunction in reward processes, craving, emotion dysregulation, and inhibitory control difficulties contribute to overconsumption of food and addictive substances, respectively. There are some unique aspects to both perspectives to consider as well. From a traditional eating disorder perspective, the role of shape and weight concern and attempts at dietary restriction are thought to be causal. From an addiction perspective, these aspects could still be considered important, but would not be as central. In contrast, the nature of the food itself would be extremely important from an addiction perspective. From a traditional eating disorder perspective, the role of the food itself is minimized. However, from an addiction perspective, certain foods (likely highly processed foods) may be so rewarding that they are capable of triggering addictive changes in reward and motivational circuitry.
Research on how food addiction runs in families is only starting to emerge. In a recent study, we found that parents with higher food addiction scores also have children with higher food addiction scores. There are a number of factors that could contribute to this, including genetics, parenting practices, and the home food environment. We definitely need more research on this topic! And we need to provide parents with tools on how to optimally feed a child who has an addictive-like drive for highly processed foods. Right now there is very little guidance out there for parents, but definitely lots of blame. As researchers and clinicians, we need to do a better job equipping parents with empirically supported practices that is sensitive to the individual needs of their child. It is highly unlikely that a one-size fits all approach to feeding is going to be successful for all children, especially those at risk for food addiction.
We do see that the YFAS is associated with a number of important co-morbidities, including obesity, diet-related disease and eating disorders. It is also associated with depression, PTSD, and gambling. My instinct is that transdiagnostic treatment approaches that focus on shared mechanisms across disorders (e.g., emotion regulation, inhibitory control) are going to be important for addressing these comorbidities.
Jiménez-Murcia1, S., Granero, R., Wolz, I., Baño, M., Mestre-Bach, G., Steward, T., Agüera, Z., Hinney, A., Dieguez, Casanueva, F.F., Gearhardt, A.N., Hakansson, A., Menchón, J.M., & Fernandez-Aranda, F. (In Press). Food addiction in gambling disorder: frequency and clinical outcomes. Frontiers in Psychology.
(Burrows, T. , Skinner, J., Joyner, M.A., Palmieri, J., Vaughan, K., & Gearhardt, A.N. (2017). Food addiction in children: Associations with obesity, parental food addiction and feeding practices. Eating Behaviors. 26, 114-120.)
Craving is also essential in the context of food addiction. I think one of the misconceptions about addiction is that people who struggle are individuals who just like the drug more, but research hasn’t really born that out. Instead, it seems to be that people who experience greater wanting and motivational drive for the substance (regardless of how much pleasure they get when they actually consume it) are at the greatest risk. This enhanced motivational drive can express itself in the form of conscious cravings or sometimes automatic approach tendencies that can occur outside of the person’s awareness. I think that equipping patients with a greater understanding of what triggers this enhanced motivational drive for them (e.g., cues in the environment, emotional states) is essential in giving them back control of their eating behavior.
Can you describe the FAST Lab, what you have done in this lab and what you hope to do going forward?
At Yale, one of my mentors was Dr. William Corbin and he has a simulated bar lab. I got to see firsthand how important it was to investigate addictive behaviors in naturalistic, cue-rich environments. The experience of drinking a beer in a sterile, clinical room is so different than the typical experience of consuming alcohol. If we do research only in sterile, hyper-controlled environments, we don’t see the craving, expectancies and behavior that are really key to problem drinking. Using Will’s work as an inspiration, I created the Food Addiction Science and Treatment lab to create a naturalistic, cue-rich food environment that resembles a fast food restaurant. It has furniture and menu boards to resemble a fast food restaurant, all our research assistants wear a uniform that resembles a fast food worker and it smells like French fries when the participants walk in. We have been using this lab to identify what are the mechanisms through which people are prone to overeat (craving being a big one!) and now we are investigating how neural responses to food advertisements might predict eating behavior in our fast food restaurant lab.
There is interesting work suggesting that individuals who have weight loss surgery are at greater risk for the development of substance use disorders. Although there are many factors that likely contribute to this (e.g., different rates of absorption of drugs, increased access to pain killers after surgery), one hypothesis is that there is an addiction transfer from highly processed foods to drugs of abuse post-surgery. Dr. Gold was one of the first researchers to publish work on how individuals who are attempting to quit drugs of abuse are at greater risk for weight gain and overeating. The research on weight loss surgery suggests this increased risk might also go the other direction too.
Ivezaj, V., Stoeckel, L. E., Avena, N. M., Benoit, S. C., Conason, A., Davis, J. F., Gearhardt, A. N., Goldman, R., Mitchell, J. E., Ochner, C. N., Saules, K. K., Steffen, K. J., Stice, E., and Sogg, S. (July 2017) Obesity and Addiction: Can a Complication of Surgery Help Us Understand the Connection? Obesity Reviews, 18, 765-775.
It is an exciting time to be doing research in this field and there are definitely more questions than answers. Some big future directions that come to mind for me are 1) identifying why certain foods are more capable of triggering an addictive process than others, 2) the development of new treatments that take into account the potentially addictive nature of highly processed foods, 3) investigating how addictive-like eating may emerge in children and teenagers, and 4) conducting more detailed research on the withdrawal syndrome that may result from cutting back on potentially addictive foods.