New research into food addiction — more likely eating addiction — has revealed a connection between compulsive eating and reduced learning abilities. The impairment can happen very fast.

A group of researchers from Australia performed a study where they provided participants with two different breakfasts, one high in fats, sugars and ultra-refined foods and the other with “healthy foods.” They did this for four consecutive days, and measured the following for changes:

• hippocampal-dependent learning and memory (HDLM)
• perception of internal bodily state (interoception)

HDLM, as the name implies, is associated with the ability to learn and create memories. Interoception is related to a person’s ability to gauge their own biological state and is associated with learning disorders including disorders of diminished motivation (impairments in goal-directed behavior, thought and emotion).

The results of the study are in: “A four-day Western-style dietary intervention causes reductions in hippocampal-dependent learning and memory and interoceptive sensitivity.” Ouch! Just four days of high-fat, high-sugar breakfast correlated with the following results: “significant reductions in HDLM and reduced interoceptive sensitivity to hunger and fullness.” That means they performed noticeably more poorly on memory tests and were less able to judge when they had eaten enough.

A much more rigorous study involves brain scans of people suffering from food addiction according to the Yale Food Addiction Scale. The study was conducted by a team of neurobiologists from with the G. Oppenheimer Family Center for Neurobiology of Stress and Resilience, Ingestive Behavior and Obesity Program in Los Angeles. Let’s cut to the chase and see what they found:

The maladaptive food behaviors displayed by individuals with food addiction serve as a coping mechanism in response to pathological anxiety and stress.

Boom, there it is: Eating addiction (not food addiction) is a coping mechanism in response to anxiety and stress. The eating addiction does not derive from the sugary, fatty foods but from the underlying stress and anxiety. Ultra-processed foods complicate the story by being dopamine inducers and weight increasers designed to soothe anxiety and stress through continuous consumption.

The study involved 150 adults from ages 18-55 with a high BMI (25+). Out of those, 103 identified as female and 47 identified as male. Forty participants scored as “food addicted” and 110 did not. The participants underwent functional magnetic resonance imaging (fMRI). Participants with food addiction scored higher on food cravings, anxiety and depression. 

A graphical representation of the results comparing the scans of the 40 “food addicted” participants with the 110 who were not is shown below.

Figure 1: Connectogram depicting food addiction-dependent differences in brain connectivity (food addiction vs. no food addiction). Used under Fair Use: Commentary.

“Our results support the hypothesis that altered connectivity in reward regions could increase the risk for addictive ingestive behaviors,” say the researchers. In one very important paragraph, the researchers tie together food addiction, dopamine, and drug addiction:

Uncontrollable eating seen in food addiction, can be explained by the reward deficiency hypothesis which states that a decreased availability of dopamine receptors, specifically D2 receptors, creates a less responsive reward system that is susceptible to addictive pathologies. Drug-addiction studies have associated drug-dependence with changes in the dopamine receptor availability, with individuals with decreased receptors seeking greater and more frequent reward stimulation.

That brings us all the way back to the connection between eating addiction and difficulties with learning and memory formation. This survey seems to indicate similar forces are at work in the brain between eating addiction, drug addiction, smartphone addiction, and other compulsive behaviors that involve dopamine fatigue and the brain’s reward system.

Written by Steve O’Keefe. First published March 18, 2024.

Sources:

“A four-day Western-style dietary intervention causes reductions in hippocampal-dependent learning and memory and interoceptive sensitivity,” PLOS ONE, February 2017.

“Alterations in reward network functional connectivity are associated with increased food addiction in obese individuals,” Science Reports, February 2021.

Image Copyright: Elnur.