Addiction does not necessarily involve what we know as traditionally addictive substances such as heroin, cocaine and nicotine. According to a new study headed by University of Michigan professor Ashley Gearhardt, ultra-processed foods (UPF) in carbohydrates and fats can also trigger an addiction.

The study published in the peer-reviewed British Medical Journal analyzed the findings of 281 nutritional studies conducted in 36 countries. They suggested that there should be addiction warning labels on some of the most popular snack foods like chips and cookies, writes High Times' A.J. Herrington.

The research revealed that 14% of adults and 12% of children are addicted to UPFs found in such snacks as ice cream, sugary soft drinks and cookies.

"The combination of refined carbohydrates and fats often found in UPFs seems to have a supra-additive effect on brain reward systems, above either macronutrient alone, which may increase the addictive potential of these foods," wrote the authors. Gearhardt's extensive experience in this field involves developing the Yale Food Addiction Scale (YFAS) using the same criteria utilized to diagnose substance addiction.

The reason why UPFs are so addictive is not yet understood though one explanation is due to the high content of both fat and carbohydrates, which causes a spike in dopamine and then a steep decline in the neurotransmitter. This creates a cycle of craving, satisfaction and crashes as is the case with drugs and alcohol. Other experts think that a combination of UPFs consumed could also be the cause of addiction.

Addictive products are not habit-forming for everyone, as there are people who can consume cocaine and not develop an addiction. Researchers say that 14% of people addicted to easily accessible ultra-processed foods is not an insignificant number and more research is necessary.

"Research has generally focused on single ingredients in UPFs, and further study is needed to investigate how UPF ingredients interact to increase addictive potential," concluded the researchers.