UPFs – foods and beverages that, as the name suggests, have undergone extensive processing – are on the rise globally. Across Europe, UPFs account for over a quarter (27%) of the average daily calorie intake, rising to more than half in the UK, US, and Canada.

Research published in The BMJ that analysed 281 studies in 36 countries, by scientists from the US, Spain, and Brazil, found that around one in seven (14%) adults and one in eight (12%) children are addicted to UPFs.

In comparison, levels of addiction in adults for alcohol and tobacco stood at 14% and 18% respectively. The researchers described the rate of addiction in children (12%) as “unprecedented”.

UPF delivery rate linked with addiction

The study suggests that UPFs, which contain high levels of refined carbohydrates and added fats, can have a “supra-additive effect” on brain reward systems and could therefore be regarded as addictive substances.

Compared to whole foods, UPFs deliver carbohydrates and fats to the gut at a much faster rate. In the same way that faster-acting routes of administration increase the addictive potential of drugs such as cocaine and nicotine, the delivery rate of UPFs positively correlates with addiction, the study found.

The prevalence of food addiction, measured by the Yale Food Addiction Scale (YFAS), resembles addiction levels seen for substances such as alcohol (14%) and tobacco (18%) in adults.

Created in 2009 to measure food addiction, the YFAS is based on the standard diagnostic criteria for a range of addictive substances including nicotine, alcohol, cocaine, and heroin. The scale measures behaviours such as lack of control over consumption, continued use regardless of negative effects, excessive intake, and withdrawal. Food addiction is classified by the presence of two or more symptoms, as well as “significant impairment or distress”.

Additives boost addictiveness of foods

Additives used commonly in UPFs to increase sweet and salty flavours may contribute significantly to their addictiveness, the study suggests. By enhancing flavour, mouthfeel, and texture, certain additives increase the palatability and appeal of food products, resulting in heightened cravings and consumption.

The study draws parallels with the use of additives in the tobacco industry to increase addiction to cigarettes. According to the study, artificial sweeteners in UPFs can intensify the rewarding effects of such products, similar to the role of menthol flavouring in increasing nicotine-evoked dopamine in cigarettes.

Additives themselves may not be addictive but they have the potential to reinforce the effects of calories in the gut, the research found.

While further in-depth research into the link between UPFs and addiction is required, the research confirms that humans consume foods high in refined carbohydrates and added fats in addictive patterns, resulting in negative health implications.

According to the researchers, refined carbohydrates or fats created “similar levels of extracellular dopamine in the brain striatum to those seen with addictive substances such as nicotine and alcohol”.

Regulation needed to protect public health

Aside from the link with addiction, high consumption of UPFs has been associated with more severe health issues and clinical complexities. Early studies show that these foods are often loaded with added sugars, unhealthy fats, and sodium, and lack the essential nutrients and minerals needed to sustain nutrition.

Regular consumption has been linked to an increase in the adult obesity rate, which currently stand at around 15% globally, data from the World Health Organization (WHO) shows. Each 10% increase in the consumption of UPFs is associated with a 12% greater risk of cancer, according to a study published in The BMJ.

However, UPF addiction lacks an official diagnosis. If, supported by scientific evidence, these foods were classed as addictive substances, policy approaches akin to those put in place to address alcohol or tobacco addiction could be developed.

Some countries have already taken steps to curtail the consumption of UPFs, such as Chile, which was the first country in the world to mandate “high-in” front-of-pack nutrition label requirements on energy-dense foods in 2014.