Dopamine and Eating Behavior

Dr. David Wiss

February 1, 2022

Addictions

How does Dopamine Interact with Eating Behavior?

In recent years, there has been an explosion of human research suggesting that ultra-processed foods can have addictive qualities. The field of food addiction was pioneered in animal models of sugar intake, where rats showed signs of behavior not unlike the effects of drug abuse, including the escalation of daily sugar intake, increases in extracellular dopamine, and signs of dependence [1].

This research contributed to our present understanding of how the dopaminergic system is involved in reward and its function in hedonistic reward associated with the consumption of highly palatable foods [2]. Human studies have shown overlapping neuroimaging characteristics in individuals with obesity and substance use disorders, specifically, reductions in dopamine D2 receptors [3]. 

Other human studies using the Yale Food Addiction Scale [4] have provided evidence for social and contextual-related factors such as impairment and efforts to control use, which strongly support the concept that ultra-processed foods with added sweeteners and fats have addictive potential in humans, not unlike drugs of abuse [5–7].

The concept of food addiction is somewhat controversial for a few reasons. The first argument against food addiction is that food is necessary for survival, therefore, cannot be addictive. However, it is important to acknowledge that ultra-processed foods with added sugars, salts, and fats, are not essential for survival; therefore, it is critical to discern between whole food (e.g., bananas, almonds) and ultra-processed food (e.g., cookies, chips).

The second argument against food addiction is that efforts to restrict intake and engage in dieting behaviors are primary drivers of food addiction symptoms. This argument is valid in many cases of food addiction, however, there are plenty of instances where individuals demonstrate addictive-like eating in the absence of dietary restraint [8,9]. 

A final argument against food addiction is that there is limited scientific support for novel and successful treatment based on the food addiction construct. Without evidence-based treatment, a “diagnosis” is generally not helpful. Many people equate food addiction with diet culture, and we think this is an oversimplification and not supported by science.

Rather than debating the clinical utility of the food addiction construct, we suggest that much of the research on this topic can be informative for understanding eating behavior. First, it is crucial to recognize that dopamine is not the only neurotransmitter involved in addictions. The opioid system, GABA, glutamate, and others have been implicated in various addictions [10]. Additionally, recent evidence suggests that dopamine is not simply a signal of reward but of anticipated reward, indicating that it is important for learned behaviors and motivation [11,12]. The ventral striatum is the region of the brain responsible for assigning value to rewarding events so that the individual can remember that behavior and repeat it (known as “salience”), largely managed through dopamine transmission.

Using this model of anticipated reward from food, it is safe to say that people experience different dopamine responses to highly palatable foods. Differences can be due to genetic and sociocultural factors, exposure to early life adversity and other forms of stress and trauma (including socioeconomic disadvantage) throughout the lifespan [7], and differing levels of exposure to ultra-processed foods. For this reason, some people can “take it or leave it” when it comes to dessert, and others that experience obsessive-like thinking and even bingeing once they begin to consume dessert foods.

Too often, people end up in polarizing camps regarding food philosophies. One camp suggests that if food is addictive, it should be eliminated entirely to return the dopamine system to homeostasis. Another camp believes that regular inclusion of these foods will desensitize the reward system and make it easier to consume these foods without the risk of bingeing. Both ideas have merit! However, at Wise Mind Nutrition, we take the position that one should not have to choose between binaries. Instead, each person should find their personal “sweet spot” (no pun intended) and determine how much ultra-processed foods to consume based on their unique neurobiology.

Clinicians who treat eating disorders are likely to pull their clients toward their camp. We don’t want to pull you anywhere. Instead, we want to empower you to find out what is sustainable for you. If quitting sugar always leads to binge eating, perhaps that approach is not right for you (or perhaps you are lacking adequate social support). If overeating ultra-processed foods over-activates your reward system and prevents you from being your best self, maybe it is wise to consume less. 

We cannot know for certain what is true for you without a comprehensive intake and assessment, as this truth can evolve over time. Many people who cut out sugar find that they can include sweet foods in moderation later in life. Many people who consume highly palatable foods can find themselves eating less as their life circumstances change. It is important to keep an open mind.

Ultra-processed foods are ubiquitous in society. The conversation of food addiction may be more relevant for public health and food policy discussions than individual-level treatment. In the meantime, we want to help you find your sweet spot so that your journey to improved mental health can continue. Unfortunately, too many people are overly restrictive with food choices, and this has led to a surge in binge eating disorders. At Wise Mind Nutrition, we have no judgment about your ongoing quest to make peace with food. We are here to help you get into recovery and stay there!

If you are looking for counseling for food addiction, or food addiction treatment, our approach is trauma-informed and eating disorder friendly. Don’t hesitate to reach out and set up a chat. 

References

1. Avena NM, Rada P, Hoebel BG. Evidence for sugar addiction: Behavioral and neurochemical effects of intermittent, excessive sugar intake. Neurosci Biobehav Rev. 2008;32(1):20–39.

2. Wiss DA, Avena N, Rada P. Sugar Addiction: From Evolution to Revolution. Frontiers in Psychiatry. 2018;9:545.

3. Volkow ND, Wise RA. How can drug addiction help us understand obesity? Nature Neuroscience. 2005;8(5):nn1452.

4. Gearhardt A, Corbin W, Brownell K. Preliminary validation of the Yale Food Addiction Scale. Appetite. 2009;52(2).

5. Gordon EL, Ariel-Donges AH, Bauman V, Merlo LJ. What Is the Evidence for “Food Addiction?” A Systematic Review. Nutrients. 2018;10(4):477.

6. Sarkar S, Kochhar KP, Khan NA. Fat Addiction: Psychological and Physiological Trajectory. Nutrients. 2019;11(11):2785.

7. Wiss DA, Avena N, Gold M. Food Addiction and Psychosocial Adversity: Biological Embedding, Contextual Factors, and Public Health Implications. Nutrients. 2020;12(11):3521.

8. Wiss DA, Avena NM. Food Addiction, Binge Eating, and the Role of Dietary Restraint: Converging Evidence from Animal and Human Studies. In: Frank KW, Berner LA, editors. Switzerland: Springer Nature; 2020. p. 193–209.

9. Wiss D, Brewerton T. Separating the Signal from the Noise: How Psychiatric Diagnoses Can Help Discern Food Addiction from Dietary Restraint. Nutrients. 2020;12(10):2937.

10. Volkow ND, Wang G-J, Fowler JS, Tomasi D, Telang F. Addiction: Beyond dopamine reward circuitry. Proc National Acad Sci. 2011;108(37):15037–42.

11. Salamone JD, Correa M. The Mysterious Motivational Functions of Mesolimbic Dopamine. Neuron. 2012;76(3):470–85.

12. Langdon AJ, Daw ND. Beyond the Average View of Dopamine. Trends Cogn Sci. 2020;