Addictive foods and the diabetes epidemic: Gearhardt testifies before U.S. Senate committee

Over the past few decades, type 2 diabetes and obesity rates have soared in the United States, presenting significant public health challenges and an urgent need to address the various drivers of these epidemics.

Ashley Gearhardt, Ph.D., M.Phil., M.S., U-M professor of psychology and a member of the Institute for Healthcare Policy & Innovation, along with four other witnesses, testified before the U.S. Senate Committee on Health, Education, Labor, and Pensions on December 14 in a hearing about factors contributing to and options to address the obesity and diabetes epidemics. She shared her expertise on the role of addiction to ultra-processed foods in the development of obesity and type 2 diabetes.

The hearing titled “What is fueling the diabetes epidemic?” is available to watch here.  

“The American diet is now composed mostly of ultra-processed foods, which are industrially manufactured products that contain little, if any, whole foods, and are a major source of added sugars and saturated fats in our diets,” Gearhardt explained in her testimony. “[These] foods activate reward systems in the brain in an analogous manner to addictive substances like nicotine.”

She cited research from her Food and Addiction Science and Treatment Lab team, as well as studies by several other experts, on how addictive properties of ultra-processed foods may drive excessive consumption among children and adults of all ages.

Among the research referenced in her testimony was a 2021 systematic review of over 280 studies that found an estimated 14% of adults and 12% of children met the criteria for an addictive disorder in their intake of ultra-processed food. These results align with findings from her research collaboration with the U-M National Poll on Healthy Aging, which showed that 13% of U.S. adults aged 50 to 80 met criteria for clinically significant ultra-processed food addiction. The systematic review co-authored by Gearhardt also indicated that the addictive pattern of ultra-processed food intake is associated with a more than five times greater occurrence of type 2 diabetes.

Gearhardt spoke further about her experiences as a licensed clinical psychologist and researcher connecting directly with people struggling to gain control of their eating habits. She shared a representative perspective from one of her research participants with type 2 diabetes who reported finding it difficult to resist eating an excessive amount of unhealthy food despite knowing the serious health risks of doing so as a diabetic.

“If addictive mechanisms are being triggered by ultra-processed foods, this may be an overlooked reason why it can be challenging to reduce intake even in the face of health conditions like diabetes,” said Gearhardt.

Her written testimony highlighted several considerations for Congress to help reduce Americans’ excessive intake of ultra-processed foods and support a food supply that promotes health.

Referencing the successful public health campaigns to decrease tobacco use in the U.S., she discussed a comprehensive approach that combines educational programs on healthy eating, improvements in food labeling, economic incentives to encourage people to buy healthier options, and limitations on marketing for ultra-processed foods. She also emphasized the need for investment in further research to better understand how ultra-processed foods activate mechanisms of addiction and contribute to excessive intake.

“Lessons learned from the tobacco epidemic can help guide solutions here,” Gearhardt told the senators. “Multipronged approaches and a focus on prevention, particularly for youth, will be important for improving Americans' health.”

More about Gearhardt’s work: 

• U-M expert profile
• U-M National Poll on Healthy Aging Report: Addiction to Highly Processed Food Among Older Adults
• Study: Highly processed foods can be considered addictive like tobacco products
• Study: Junk food ads trigger positive emotions, healthy foods not so much