A recent Frontiers in Nutrition study assesses the association between metabolic diseases and the consumption of ultra-processed foods (UPFs). 

Study: Ultra-processed food consumption and metabolic disease risk: An umbrella review of systematic reviews with meta-analyses of observational studies. Image Credit: JeniFoto / Shutterstock.com

Background

Reducing the consumption of UPFs is usually really helpful to stop the event of metabolic diseases like type 2 diabetes mellitus (T2DM) and obesity. Metabolic diseases adversely affect organs, tissues, or cells and are attributable to the decomposition and abnormal synthesis of certain substances during metabolism.

The precise etiology of metabolic diseases stays unclear. Nevertheless, each environmental and genetic aspects influence their occurrence, amongst which weight loss program is an easily modifiable environmental factor.

The NOVA food classification system defines UPFs as a category of foods arising from industrial formulations created from extracted substances, additives, and little intact food. Examples of UPFs include cakes, snacks, sausages, and sweetened beverages.

Research has identified an association between various metabolic diseases and UPF consumption. Nevertheless, some query this association, claiming that these relationships established within the literature are liable to biases.

In regards to the study

The current study involved an umbrella review (UR), by which published systematic reviews were analyzed with meta-analyses to evaluate their credibility and validate the robustness of the connection between metabolic disease and UPF consumption.

The Web of Science, PubMed, Embase, and Cochrane Library databases were systematically searched until July 15, 2023. Language restrictions weren’t imposed, and citations of included studies were monitored to detect additional eligible studies.

Articles involving laboratory and animal studies, in addition to genetic polymorphisms, were excluded. Moreover, studies unable to acquire study-specific data, those without quantitative evaluations, and those who included fewer than three original studies were excluded from the meta-analyses. 

Key findings

An intensive overview of 13 meta-analyses was performed to guage the credibility of relationships between the consumption of UPFs and metabolic disease. To this end, all studies suggested that the consumption of UPFs was related to the event of obesity and T2DM. 

The very best level of UPF consumption and a 1.55-fold higher obesity risk were established in seven cross-sectional studies and a number of other prospective cohort studies; subsequently, UPF consumption might be considered a risk factor for obesity. These findings indicate that there could also be health advantages related to reducing the consumption of UPFs. This ought to be considered in the longer term by healthcare professionals and policymakers while formulating dietary guidelines.

Two meta-analyses revealed a major association between UPF consumption and T2DM, thus suggesting that consuming UPFs might be a risk factor for developing T2DM. Inside UPFs, processed meat and sugar-sweetened beverages were strongly related to the danger of T2DM, with the dose of those UPFs potentially dictating this association.

Within the moderate and lowest meta-analysis, the association between T2DM and UPFs was supported by weak evidence. This association was insignificant within the Asian population. 

The consumption of UPFs was also related to an increased risk of non-alcoholic fatty liver disease (NAFLD), hypertension, and metabolic syndrome (MetS). Nevertheless, these associations weren’t robust across subgroups, which necessitates the necessity for extra studies to explore these associations.

Conclusions

The present study provides evidence that the consumption of UPFs is related to a greater risk of metabolic diseases, particularly obesity and T2DM. For other metabolic diseases, the associations ought to be explored further in future studies.

The most important strength of this study is the great assessment of the standard and credibility of every meta-analysis. In actual fact, that is the primary UR to supply an in depth summary of the association between metabolic diseases and UPF consumption.

One limitation of this study might be as a result of underlying studies lacking specific data or the exclusion of studies by previous meta-analyses. Future studies should address this concern by including other consequence variables, comparable to hyperuricemia and dyslipidemia. Residual confounding and measurement errors were also not considered as a result of the dearth of randomized controlled trials. 

Few underlying studies used the NOVA classification system to define UPFs, and a few meta-analyses concurrently included studies that used the NOVA system and those who didn’t. This made it difficult to keep up consistency while reporting findings and will have led to the misclassification of UPFs.

The generalizability of the outcomes might be questioned, as most studies were conducted in the USA, across several European countries, and Brazil.