Are some food products addictive?

Researchers from the United States, Brazil and Spain have published an analysis in the British Medical Journal, calling for a shift in the way we think about ultra-processed food.

“By acknowledging that certain types of processed foods have the properties of addictive substances, we may be able to help improve global health,” said Ashley Gearhardt, the article’s corresponding author and a psychology professor at the University of Michigan.

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

According to the researchers, not all foods have the potential for addiction. Foods that are natural, or minimally processed, provide energy in the form of carbohydrate or fat, but not both.

For example, an apple has a carbohydrate to fat ratio of roughly 1:0, while salmon has a ratio of 0:1. In contrast, a chocolate bar has a carbohydrate to fat ratio of 1:1, which appears to increase a food’s addictive potential.

“Many ultra-processed foods have higher levels of both. That combination has a different effect on the brain,” DiFeliceantonio said. Researchers also called for more study into the role of food additives used in industrial processing.

The co-authors represent international expertise on food addiction, nutrition physiology, gut-brain reward signalling, food policy, behavioural addiction and eating disorders.

“Given how prevalent these foods are — they make up 58% of calories consumed in the United States — there is so much we don’t know.” DiFeliceantonio said.

The researchers have called for more study into such areas as: how complex features of ultra-processed foods combine to increase their addictive potential; better defining which foods can be considered addictive; differences among countries and communities, including disadvantaged communities; the value of public-health messaging; and clinical guidelines for preventing, treating and managing addiction to ultra-processed foods.

Image credit: Clayton Metz/Virginia Tech