Association between Ultra-Processed Food Consumption and Metabolic Syndrome among Adults in China-Results from the China Health and Nutrition Survey

Examining the evidence between screen time and night eating behaviour with dietary intake related to metabolic syndrome: A narrative review

Screen time (ST) on digital devices has increased in recent decades due to digital development. Furthermore, constant engagement with digital devices alters sleep patterns, leading to nocturnal eating behaviour among users. These phenomena are therefore of great concern, as digital device addiction and night eating are associated with unhealthy food intake, increasing the metabolic syndrome (MetS) risks. The purpose of this review was to examine the evidence of the influence of ST and night eating behaviour (NEB) on dietary intake and its association with MetS based on previous literature. Prolonged ST and NEB have an association with excessive intake of energy from overconsumption of high-sugar and high-fat foods. However, the relationship between digital content and its influence on food intake is inconsistent. A higher MetS risk was found in individuals with longer ST due to a sedentary lifestyle, while positive energy balance and a shift in circadian rhythm contributed to night eaters. ST and NEB presented with a significant influence on food intake in adults. Additionally, unhealthy food intake due to excessive consumption of empty-calorie foods such as sweet and fatty foods due to addiction to electronic devices and eating at night has a detrimental effect on metabolic function. Therefore, improving food intake by reducing ST and night binges is essential to reduce the risk of MetS.

Ultra-processed Food and Obesity: What Is the Evidence?

PURPOSE OF REVIEW

Obesity is a growing global healthcare concern. A proposed driver is the recent increase in ultra-processed food (UPF) intake. However, disagreement surrounds the concept of UPF, the strength of evidence, and suggested mechanisms. Therefore, this review aimed to critically appraise the evidence on UPF and obesity.

RECENT FINDINGS

Observational studies demonstrate positive associations between UPF intake, weight gain, and overweight/obesity, more clearly in adults than children/adolescents. This is supported by high-quality clinical data. Several mechanisms are proposed, but current understanding is inconclusive. Greater UPF consumption has been a key driver of obesity. There is a need to change the obesogenic environment to support individuals to reduce their UPF intake. The UPF concept is a novel approach that is not explained with existing nutrient- and food-based frameworks. Critical analysis of methodologies provides confidence, but future observational and experimental research outputs with greater methodological rigor will strengthen findings, which are outlined.

Ultra-processed food consumption and non-alcoholic fatty liver disease, metabolic syndrome and insulin resistance: A systematic review

Background

High ultra-processed food (UPF) consumption is associated with the development of various diet-related non-communicable diseases, especially obesity and type 2 diabetes. The present study aimed to systematically review the association between UPF consumption and non-alcoholic fatty liver disease (NAFLD) and its leading risk factors; metabolic syndrome (MetS) and insulin resistance (IR).

Methods

A comprehensive search was conducted in PubMed, Scopus, Embase, Web of Science, CINAHL, and Cochrane (March 2023), and references of the identified articles were checked. The search keywords were defined through an exploratory investigation in addition to MeSH and similarly controlled vocabulary thesauruses. Observational and interventional studies were included. Studies that focused only on specific groups of processed foods or overlapping dietary patterns were excluded. The quality assessment was conducted using the Joanna Briggs Institute's critical appraisal tools for observational studies and Cochrane's risk of bias 2 tool for randomized-control trials. A narrative synthesis was employed to report the results.

Results

Fifteen studies were included, with a total of 52,885 participants, one randomized-controlled trial, and fourteen observational studies (nine cross-sectional and five prospective). The review has shown a significant association between UPF consumption and NAFLD in three studies out of six, MetS in five out of eight, and IR in one out of three. All large-scale prospective cohorts that studied NAFLD or MetS outcomes demonstrated a positive association. In contrast, studies that did not demonstrate significant associations were mostly cross-sectional and small. The evidence for an association with IR was insufficient and conflicting.

Conclusion

The included studies are few, observational, and based upon self-reported dietary assessment tools. However, current evidence indicates that UPF is not only associated with obesity and type 2 diabetes but may also be a risk factor for NAFLD and MetS. UPF is a worldwide concern deserving further longitudinal research.

Impact and implications

Overconsumption of ultra-processed food (UPF) may lead to the development of obesity and type 2 diabetes, but the association with non-alcoholic fatty liver disease (NAFLD) is not well established. The present systematic review shows that UPF may be associated with NAFLD, although more large prospective studies are needed. These findings emphasize the importance of minimizing the consumption of UPF to prevent NAFLD and other metabolic diseases among the general adult population. This systematic review and further prospective studies, epidemiological or interventional, can help physicians provide patients with evidence-based nutritional recommendations and will support policymakers in restricting the marketing of UPF as well as promoting affordable, healthy, and minimally processed foods.

Oxidative Stress and Inflammatory Biomarkers Are Related to High Intake of Ultra-Processed Food in Old Adults with Metabolic Syndrome

In the last few decades the consumption of ultra-processed foods (UPFs) worldwide has substantially augmented. Increasing evidence suggests that high UPF consumption is associated with an increase in non-communicable diseases, being overweight, and obesity. The aim of this study was to assess how UPF consumption affects oxidative and inflammatory status in the plasma, neutrophils, and urine of old adults with metabolic syndrome. Participants (n = 92) were classified into two groups according to UPF consumption. Dietary intakes were measured by a validated semi-quantitative 143-item food frequency questionnaire and UPF consumption was determined according to the NOVA classification system. Low UPF consumers showed higher adherence to the Mediterranean diet than high UPF consumers. A high intake of fiber and a high concentration of polyphenols in urine were also observed in subjects with low UPF consumption. Despite the absence of differences in biochemical profile, oxidative and inflammatory biomarkers showed some significant changes. Catalase and superoxide dismutase activities were lower in high UPF consumers, whereas myeloperoxidase activity was higher. ROS production in neutrophils stimulated with zymosan was higher in high UPF consumers than in low UPF consumers. Biomarkers such as xanthine oxidase, tumor necrosis factor α (TNFα), interleukin (IL)-6, IL-15, and leptin levels were higher in participants with high intake of UPF. No differences were found in malondialdehyde and other inflammatory cytokines. The current study evidenced that MetS participants with high UPF consumption have a more pro-oxidant and inflammatory profile than those with low UPF consumption, despite showing similar blood biochemical profiles.

Ultra-processed food consumption and increased risk of metabolic syndrome: a systematic review and meta-analysis of observational studies

Background

Although higher consumption of ultra-processed food (UPF) has been linked to a higher risk of metabolic syndrome (MetS), the results remain controversial. Herein, we performed a systematic review and meta-analysis of observational studies to clarify the relationship between UPF consumption defined by the NOVA framework and risk of MetS.

Methods

An extensive literature search on PubMed, ISI Web of Science, EBSCO and China National Knowledge Infrastructure (CNKI) databases was conducted to search for the relevant articles published priori to January 2023, and newly published articles between January 2023 and March 2023 were re-searched. Random-effects or fixed-effects models were adopted to calculate the pooled relative risks (RRs) and 95% confidence intervals (CIs). The between-study heterogeneity was explored using the Cochran's Q test and I-square (I²). Publication bias was investigated using the visual inspection of asymmetry in funnel plots and Begg's and Egger's tests.

Results

Nine studies (six cross-sectional and three prospective cohort studies) totaling 23,500 participants with 6,192 MetS cases were included in the final analysis. The pooled effect size for the highest vs. lowest categories of UPF consumption indicated a positive association with the risk of MetS (RR: 1.25, 95%CI: 1.09-1.42, P < 0.0001). Subgroup analyses revealed a positive association between consumption of UPF and MetS risk in cross-sectional studies (RR: 1.47, 95%CI: 1.16-1.87, P = 0.002), and no significant association in cohort studies (RR: 1.10, 95%CI: 0.96-1.27, P = 0.104), respectively. In addition, a more significant association between UPF consumption and increased risk of MetS was found in the subgroups of study quality <7 (RR: 2.22; 95%CI: 1.28-3.84, P = 0.004) than study quality ≥7 (RR: 1.20; 95%CI: 1.06-1.36, P = 0.005). Similarly, when we performed analyses separately by sample size, there was a significant association between UPF consumption and MetS risk in sample size ≥5,000 (RR: 1.19; 95%CI: 1.11-1.27, P < 0.0001), and in sample size <5,000 (RR: 1.43; 95%CI: 1.08-1.90, P = 0.013), respectively.

Conclusions

Our findings suggest that higher consumption of UPF is significantly associated with an increased risk of MetS. Further longitudinal studies are needed to confirm the effect of UPF consumption on MetS.

Associations between Dietary Patterns, Anthropometric and Cardiometabolic Indices and the Number of MetS Components in Polish Adults with Metabolic Disorders

Diet-therapy of metabolic syndrome (MetS) is of great importance due to significant health and social consequences. The aim of this study was (1) to determine dietary patterns (DPs), and (2) to search for associations between defined DPs, anthropometric and cardiometabolic indices, and the number of MetS components in Polish adults with metabolic disorders. The study was designed as a cross-sectional. The study group was 276 adults. Data about the frequency of consumption of selected food groups were collected. Anthropometric measurements: body height (H), body weight (BW), waist (WC), and hip (HC), as well as body composition, were taken. Blood samples were obtained for measurements of glucose and lipids. The obtained biochemical and anthropometric parameters were used to calculate the anthropometric and metabolic dysfunction indices. Three dietary patterns were identified in our study group: Western, Prudent and Low Food. Results of logistic regression analysis indicated rare consumption of fish as a predictor of risk of more severe forms of MetS. The possibility of using body roundness index (BRI) for fast diagnosis of cardiometabolic risk was found. In the management of MetS, the development of strategies to reduce the risk of more severe forms of MetS should be focused on increasing fish consumption and other prohealthy food.