Identifying some foods as addictive could stimulate research, shift attitudes

October 10, 2023
Concept illustration of an assortment of highly processed foods. Image credit: Nicole Smith, made with Midjourney

Conceptualizing ultra-processed foods high in carbohydrates and fats—candy, ice cream, potato chips—as addictive substances can contribute to efforts to improve health worldwide, according to a new international study led by a University of Michigan researcher.

The scientific understanding of addiction has changed in recent years, but has often focused on smoking and drinking behaviors. Internationally, what has been considered addictive as it pertains to ultra-processed foods has become increasingly important to help people worldwide live healthier lives.

Researchers from the United States, Brazil and Spain published a newly released analysis in Food For Thought, a special edition of the British Medical Journal. One of the papers, “Social, clinical, and policy implications of ultra-processed food addiction,” involved research by Ashley Gearhardt, U-M professor of psychology who is an expert on addiction to ultra-processed food.

“There is converging and consistent support for the validity and clinical relevance of ultra-processed food addiction,” she said. “By acknowledging that certain types of processed foods have the properties of addictive substances, we may be able to help improve global health.”

Gearhardt heads a food and addiction science and treatment lab at U-M that uses a simulated fast food restaurant to study eating behaviors.

While people can give up smoking, drinking or gambling, they can’t stop eating, said co-author Alexandra DiFeliceantonio, assistant professor at Virginia Tech. The challenge is defining which foods have the most potential for addiction and why.

“Most foods that we think of as natural, or minimally processed, provide energy in the form of carbohydrate or fat—but not both,” DiFeliceantonio said.

Some of the key messages from the analysis include:

  • Ultra-processed foods high in refined carbohydrates and added fats are highly rewarding, appealing and consumed compulsively and may be addictive.
  • Behaviors around ultra-processed food may meet the criteria for diagnosis of substance use disorder in some people.
  • Ultra-processed food addiction is estimated to occur in 14% of adults and 12% of children and is associated with biopsychological mechanisms of addiction and clinically significant problems.
  • Understanding of these foods as addictive could lead to novel approaches in the realm of social justice, clinical care and policy approaches.

When it comes to policy approaches, Gearhardt points to 103 countries that have passed sugar sweetened beverage taxes and several more also taxing ultra-processed foods. A meta-analysis estimates that such taxes are associated with an average decline of 15% in SSB sales and 18% in SSB intake. Furthermore, these taxes have shown a reduction in body mass index among adolescent girls in countries such as Mexico, she said.

Another policy in more than 20 countries is nutrition labels on the front of these foods has shown a significant reduction in these purchases.

“It’s essential to understand the addiction to these ultra-processed foods globally, particularly in low- and middle-income countries,” Gearhardt said, noting these foods’ heightened appeal due to low cost, convenience and marketing. “It will take courageous action to change these and other economic and structural factors that drive people towards ultra-processed foods.”

The study’s co-authors are Nassib Bueno of Universidade Federal de Alagoas in Brazil, Christina Roberto of the University of Pennsylvania, and Susana Jiménez-Murcia and Fernando Fernandez-Aranda, of the University Hospital of Bellvitge in Spain.