Social, Clinical, and Policy Implications of Ultraprocessed Food Addiction

BMJ [British Medical Journal]
October 9, 2023; Vol. 383; Article e075354

Ashley Gearhardt, Nassib Bueno, Alexandra DiFeliceantonio, Christina Roberto, Susana Jiménez-Murcia, Fernando Fernandez-Aranda. This study cites 99 references.

KEY POINTS FROM THIS ARTICLE:

1) Ultraprocessed foods (UPFs) are the major source of refined carbohydrates and added fats in diets.

• UPFs with high levels of refined carbohydrates and fats are very accessible, convenient, and heavily marketed.

2) “The Yale Food Addiction Scale assesses all 11 symptom criteria for substance use disorder in DSM-5, including diminished control over intake, cravings, withdrawal, and continued use despite negative consequence.”

• “The YFAS has undergone rigorous psychometric testing and has strong internal consistency and test-reliability, as well as convergent, discriminant, and incremental validity.”
• “A substance use disorder is defined as the presence of two or more symptoms in the past year and clinically significant impairment or distress.”

3) “Two systematic reviews including 281 studies from 36 different countries found the overall pooled prevalence of food addiction using YFAS was 14% in adults and 12% in children.”

• “[This] prevalence is similar to the levels of addiction seen for other legal substances in adults (eg, 14% for alcohol and 18% for tobacco), but the level of implied addiction in children is unprecedented.” [Key Point]
• The prevalence of food addiction is 32% in people with obesity-bariatric surgery and “over 50% in those with binge eating disorder.”
• Food addiction is also associated with “core mechanisms of addiction, such as reward related neural dysfunction, impulsivity, and emotion dysregulation, as well as poorer physical and mental health and lower quality of life.”

4) “Refined carbohydrates or [refined] fats evoke similar levels of extracellular dopamine in the brain striatum to those seen with addictive substances such as nicotine and alcohol.” [Important]

• “Foods that deliver high levels of refined carbohydrates or added fats are a strong candidate for an addictive substance.”
  • “Ultra-processed foods (UPFs)— industrially produced foods containing ingredients not available in-home kitchens—are the main source of refined carbohydrate and added fats in the modern food supply.” [Key Point]

5) “Natural or minimally processed foods typically contain either carbohydrates or fat, they rarely contain both.”

• 100 g of apple has 55 kcal from carbohydrates and 1.5 kcal from fat (roughly 36:1).
• 100 g of salmon has 0 kcal from carbohydrates and 73 kcal from fat (roughly 0:1).

6) Many UPFs contain much higher levels of both carbohydrates and fats in more equal proportions:

• 100 g of a chocolate bar contains 237 kcal from carbohydrates and 266 kcal from fat (1:1).
• “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.” [Key Point]

7) “The speed at which UPFs deliver carbohydrates and fats to the gut may also be important to their addictive potential.”

• “Drugs and routes of administration that affect the brain more quickly have a higher addictive potential.”
• “This is the rationale behind substitution therapies and why a cigarette, which rapidly delivers nicotine to the brain, is more addictive than a slow release nicotine transdermal patch.”
• “The food matrix is altered in UPFs, which makes them easier and faster to consume, have greater bioavailability, and potentially allows them to affect the brain more rapidly.”
• “The intact food matrix of minimally processed foods slows down their rate of consumption and reduces bioavailability.” [Important]

8) “Nuts have a high[er] ratio of fat to carbohydrate than most UPFs and the fats remain encapsulated in cell walls after chewing, making them unavailable, especially at the early stages of digestion.” This is important because:

• Signaling from the lower portion of the digestive track does not evoke dopamine in the striatum.
• Signaling from the upper intestine (duodenum) does evoke dopamine in the striatum.

9) “The ability of UPFs to rapidly deliver bioavailable rewarding substances may contribute to their increased addictive potential.”

10) Additive flavors contribute to the addictiveness of UPFs.

• “Many UPFs have flavour additives that increase sweet and savoury tastes, as well as texturisers that improve the mouthfeel.”
• “Additives that aim to improve flavour and mouthfeel are also common in cigarettes, including sugar, cocoa, menthol, and alkaline salt.”

11) “In the U.S. there is a proposal to remove menthol flavoured cigarettes and flavoured cigars from the market because of their role in increasing addictive liability.”

• “[Menthol] increases nicotine evoked dopamine in the striatum.”

12) Artificial sweeteners bind to receptors in the gut, “increasing the capacity to absorb glucose.” [This is an explanation as to why those who regularly consume artificial sweeteners actually gain weight: see Article Review 15-13: Fueling the Obesity Epidemic? Artificially Sweetened Beverage Use and Long-term Weight Gain].

13) “UPFs high in refined carbohydrates and fats are clearly consumed in addictive patterns and are leading to deleterious health outcomes.” [Key Point]

14) Refined carbohydrates and fats “seem to activate neural reward systems to a similar magnitude as nicotine and ethanol.” [Very Important]

15) “Processed tobacco leaves have been available for hundreds of years for people to make their own addictive tobacco products.”

• “The invention of the cigarette roller in the 1880s made mass produced cigarettes more accessible, convenient, and heavily advertised and contributed to an over 1000% increase in cigarette smoking.” [Important]

16) “Food outlets in disadvantaged neighbourhoods are often dominated by UPFs, with limited access to minimally processed foods.”

17) “UPFs already have heightened appeal, and combined with their low cost, convenience, and marketing, it is hard for minimally processed foods to compete, particularly for those facing the stress of structural disadvantages.”

• “This aligns with evidence that public messaging campaigns highlighting practices of the tobacco industry such as predatory marketing and engineering addictive products were effective in driving public attitudes against tobacco.”
• “Tobacco companies minimised the addictive nature of their products by focusing on users’ personal responsibility.”

18) “The inclusion of a UPF addiction diagnosis in clinical care would be likely to improve access to support and enable the development of treatments to reduce compulsive patterns of UPF intake.”

19) “People find it challenging to reduce intake of addictive substances even when highly motivated, which challenges the personal responsibility narrative used by industry.”

20) The authors advocate for “regulatory safeguards to curtail industry practices such as the creation of UPFs that maximise ‘craveability’ by hitting consumers’ ‘bliss point,’ and the aggressive marketing of such products to children.”

COMMENTS FROM DAN MURPHY:

This article references the books by Michael Moss:

Salt, sugar, fat: How the Food Giants Hooked Us, 2013.

Hooked: Food, Free Will, and How the Food Giants Exploit Our Addictions, 2021.

I would also recommend The End of Craving, 2022.