18 Jul Examining the arguments around ultraprocessed foods in our food system
Do ultraproccessed foods (UPFs) provide any nutritional and economic benefits? Are they implicated in negative health consequences? What is the evidence behind the association of UPF consumption with health outcomes?
Two recent reviews from the British Journal of Nutrition (BJN) and the American Society for Nutrition (ASN) provide contrasting insights on the above questions.
The NOVA food classification system segregates food into four groups: Group 1 – unprocessed and minimally processed foods; group 2 – processed culinary ingredients; group 3 – processed foods; group 4 – UPFs. UPFs within the NOVA system can serve as guidance to inform nutrition policy activities. As reported in the BJN commentary, evidence from mechanistic studies showed that altered food matrix structures and new chemical compositions in UPFs could lead to an increase in energy intake when consumed liberally, driving elevations in weight gain and body fat. This could be attributed to modifications in physiological, immunological, hormonal, or neurobiological pathways.
However, the article from ASN challenges the adoption of the NOVA system as an adequate guide for health promotion. Firstly, apart from one clinical trial, the authors assert that there is insufficient examination of the cause and effect between health outcomes and food processing. Secondly, a critical evaluation of the mechanisms by which UPFs influence food choice, food composition and digestive processes found that violations of principles in specificity, clarity and consistency are more common than the evidence to support them. For example, in terms of food composition, the NOVA system provides limited clarity on how mixed meals of differing glycaemic index values could impact appetitive responses. Thirdly, the article pointed out the potential of fortified UPFs in managing nutrient shortfalls for vitamin E, calcium, and some B vitamins.
In terms of sustainability, the commentary from BJN highlighted that UPF production contributes considerable quantities of waste and utilises many finite environmental resources. However, the ASN article suggested that the presence of preservatives in these foods increases shelf lives, thus protecting nutrient density and reducing food waste – particularly important factors for populations facing food insecurity. Furthermore, UPFs require shorter consumer preparation time and may be convenient nutrition sources for time-pressed individuals.
Overall, conclusions from both reviews showed some contention around UPFs, and whether their introduction into our modern food systems may provide more benefits or harm. The BJN article also pointed to the challenges of achieving consensus for this politicised topic, which is of great relevance to both public health and the food industry. While there may be some value to the addition of UPFs in our food, concerns around their contribution of sodium, sugar and saturated fat on long-term health must be addressed. The manufacturing process is highly variable among UPFs, so one key challenge in the NOVA classification system is to consider its ability to categorise the extent of food processing and account for differences in food formulation. Diets should be varied enough to achieve necessary nutrient and energy requirements. Hence, rather than a complete avoidance of all processed foods, perhaps the more important consideration is the quantity, frequency, and type of consumption.
This SNippet was written by Patricia Soh, a PhD Fellow in the SNi team.
Photo by Kenny Eliason on Unsplash
