There's something inexplicably moreish about pizza. Maybe it's that melted mozzarella. Or perhaps it's the delicious "umami" taste created by the cheese and tomato combination. But something about pizza means that the answer to the question "another slice?" always rhymes with "dress" (that same dress it prevents you from fitting in).
Psychologists at the University of Michigan decided to investigate which foods are actually the most addictive. They set out to rank foods on a scale of addiction, and found that eating a delicious slice of pizza is basically like shooting up heroin, but with fewer consequences of course. This could seem like common knowledge - just thinking back to the many times I've tried to stuff a forth pizza box in my trash can - but these researchers acquired this information through rigorous testing.
Graduate student Erica Schulte and Dr. Ashley Gearhardt hypothesized: "Highly processed foods share pharmacokinetic properties (e.g. concentrated dose, rapid rate of absorption) with drugs of abuse, due to the addition of fat and/or refined carbohydrates and the rapid rate the refined carbohydrates are absorbed into the system."
Essentially, they were proposing that processed foods, like bread, cheese, and bacon, are the most addictive, and I can't say I disagree. To test their theory, they showed 120 undergraduates pictures of 35 common foods. They showed them two pictures at a time and asked the students which of the two they would consider more likely to produce addiction-like eating behaviors.
Next, they obtained an even bigger sample size of 384 people. These subjects were asked to rate each food's addictiveness on a scale from 1 to 7. Pizza came out on top with a score of 4.01 followed behind by chocolate and chips, sharing second with a score of 3.73. Other addictive foods include cookies, french fries, ice cream, and soda. They also found that the least addictive foods are beans, cucumbers, and carrots.
The findings correlated with animal studies that examine levels of dopamine, our brains' "pleasure chemical" that's often linked to addiction. The researchers also looked into how gender and body mass affect levels of resistance. While gender didn't seem to affect addiction, people with higher body mass indexes reported a bit more of an addictive-like attraction to foods.
The author's overall conclusion was: "The current study provides preliminary evidence that not all foods are equally implicated in addictive-like eating behavior, and highly processed foods, which may share characteristics with drugs of abuse, appear to be particularly associated with ‘food addiction.'"
If you're struggling with an addiction to pizza, admitting it is the hardest step. Unfortunately, since there's no such thing as pizza rehab (yet), you might as well head over to your favorite parlor and pick up a slice. There's no shame in loving pizza a little too much.