Adding ultra-processing to Health Star Rating offsets ‘health halo’ effect

Making simple changes to the Health Star Rating (HSR) system to factor in ultra-processing would lower the high scores currently assigned to many unhealthy foods, according to new research published today in Nutrition and Dietetics.¹

It would also bring Australia’s main nutritional labelling system more in line with the globally recognised NOVA system, researchers from The George Institute for Global Health found.

The research team modified the algorithm behind the HSR system by deducting or capping points awarded to foods that would be classified as ultra-processed by the NOVA system. They reassessed 25,486 products in the FoodSwitch database, resulting in lower ratings for many less healthy products, such as protein bars and balls, sugary cereals, refined/’white’ breads, and diet soft drinks.

The adjusted models resulted in greater overall alignment of Health Star Ratings with NOVA, improving alignment for up to 22% more products - 88% vs 66% under the current HSR system.

“The current HSR system gives a reasonable reflection of the sugar, salt and saturated fat content of our foods and drinks but doesn’t tell us anything about how ultra-processed they are,” said lead author and dietitian Dr Eden Barrett, a Research Fellow in Food Policy at The George Institute. 

‘In the present system, manufacturers can ‘game’ the Health Stars scoring system by adding isolated fibres, proteins and artificial sweeteners that can push their HSR higher, creating a ‘health halo’ effect. As evidence on the long-term harmful effects of ultra-processing continues to emerge, it’s important to address this potentially misleading message on food labels.

“We found our modifications to the HSR algorithm penalised the most problematic products by scoring them lower, which is less confusing for consumers,” she said.

Food items that could attract lower scores when ultra-processing is factored into HSR include:

However, the modifications also lowered the HSR on some other foods like packaged wholegrain breads, and similar cereal and grain products. While these foods currently meet the ultra-processed definition, research shows that they do not seem to be associated with poorer health.² Further development of the algorithm may need to factor in ongoing evidence in this area. 

“We’re still pushing for Health Star Ratings to be mandatory, otherwise the food industry will continue to display them only on selected foods,” said Dr Alexandra Jones, Program Lead in Food Policy at The George Institute, and a lecturer in public health law at UNSW Sydney. “We also recognise the scoring system must be periodically reviewed to remain aligned with developing nutrition science. The research demonstrates practical ways to factor in ultra-processing as an important element of any future update.”

Ultra-processed foods are characterised as industrially manufactured products made using a range of chemical and physical processing techniques.³ They typically contain food substances never or rarely used in home kitchens or cosmetic additives that transform the textural and sensory properties of foods, and often contain large amounts of refined starch, added salt, and added sugar. Foods that have been disrupted in this way can make people feel less full which encourages over-eating, and consuming industrial food additives can alter gut microbiota and increase inflammation.^4,5,6 

Diets high in ultra-processed foods are associated with a raft of serious long-term health problems including type 2 diabetes, cancer, obesity and heart disease.^7,8 In many high-income countries, ultra-processed foods have been found to contribute 30-60% of total energy intake.⁴ At least seven countries recommend limiting intakes of ultra-processed foods in their national dietary guidelines.⁹ 

Consideration of ultra-processing was proposed in the last review of the now 10-year-old Health Star Rating algorithm in 2019 but was limited by a lack of practical proposals for how to achieve this. 

“Given increasing consumer and public health interest in this area, our work contributes new concrete proposals for how ultra-processing could be factored into the existing scoring system,” Dr Barrett said. “The Health Star Rating algorithm shouldn’t be viewed as something we can ‘set and forget’ but as a model that can and should be continually improved to reflect the latest evidence and enhance its ability to distinguish between healthier and less healthy products.”

References:

1. Barrett EM, Pettigrew S, Neal B, Rayner M, Coyle DH, Jones A, Maganja D, Gaines A, Mozaffarian D, Taylor F, Ghammachi N, Wu JHY, Modifying the Health Star Rating nutrient profiling algorithm to account for ultra-processing. Nutrition & Dietetics, 2024
2. Cordova R, Viallon V, Fontvieille E, et al. Consumption of ultra-processed foods and risk of multimorbidity of cancer and cardiometabolic diseases: multinational cohort study. Lancet Reg Health Eur. 2023;35:100771
3. Monteiro CA, Cannon G, Levy RB, et al. Ultra-processed foods: what they are and how to identify them. Public Health Nutr. 2019;22:936-941
4. Touvier M, et al. Ultra-processed foods and cardiometabolic health: public health policies to reduce consumption cannot wait. BMJ. 2023;383:e075294
5. Lerner A, Matthias T. Changes in intestinal tight junction permeability associated with industrial food additives explain the rising incidence of autoimmune disease. Autoimmun Rev. 2015; 14:479-489
6. Miclotte L, Van de Wiele T. Food processing, gut microbiota and the globesity problem. Crit Rev Food Sci Nutr. 2020;60: 1769-1782
7. Chen X, Zhang Z, Yang H, et al. Consumption of ultraprocessed foods and health outcomes: a systematic review of epidemiological studies. Nutr J. 2020;19:86
8. Pagliai G, et al. Consumption of ultra-processed foods and health status: a systematic review and meta-analysis. Br J Nutr. 2021;125: 308-318
9. Koios D, Machado P, Lacy-Nichols J. Representations of ultraprocessed foods: a global analysis of how dietary guidelines refer to levels of food processing. Int J Health Policy Manag. 2022;11:2588-2599
    

Leads

• Dr Eden Barrett

  Research Fellow, Food Policy