Negative impacts of ultra-processed foods pronounced in certain groups

Higher consumption of ultra-processed foods is linked to poorer physical health, with the impact being more pronounced in women, those with unhealthy lifestyles, and individuals from low socioeconomic backgrounds.

A recent BMC Public Health study assesses how lifestyle and socioeconomic factors affect the association between health-related quality of life (HRQoL) and the consumption of ultra-processed foods (UPFs).

The impact of UPF consumption on quality of life

UPFs are heavily processed food products with poor nutritional quality due to their high salt, unhealthy fat, sugar, and energy content, in addition to their low protein, micronutrient, and fiber content. Consuming UPFs increases the risk of obesity and cardiovascular diseases, as well as adverse psychological and HRQoL effects.

The relationship between HRQoL and UPF consumption may be influenced by various socioeconomic and lifestyle factors, including smoking, alcoholism, and a sedentary lifestyle. Moreover, lifestyle and socioeconomic factors may affect and regulate the association between these two variables. However, few studies to date have investigated these modifying effects.

About the study

The study cohort included individuals who participated in the Tehran Lipid and Glucose study. A total of 1,766 adults between 18 and 78 years of age were recruited for the study, 54.3% of whom were female.

To determine HRQoL, the second version of the Short-Form 12-Item Health Survey was used, which provided mental component summary (MCS) and physical component summary (PCS) scores. A validated semi-quantitative food frequency questionnaire was also used to assess the consumption of UPFs.

Socioeconomic factors like education level and employment status, as well as lifestyle patterns including physical activity and smoking status, were also determined. General linear models (GLM) were utilized to calculate the average MCS and PCS scores across the UPF tertiles. GLM was also used to study the effect of socioeconomic and lifestyle factors on the relationship between UPF consumption and HRQoL.

Study findings

Physical functioning, role physical, and PCS all significantly decreased from the first tertile of UPF consumption to the third tertile. These associations remained significant in a second model once additional confounding factors were considered. No significant associations were observed between MCS and UPF consumption except for social functioning.

Men reported higher scores for both mental and physical quality of life (QoL) than women. Non-smokers had lower PCS scores as compared to smokers.

Medium/high active individuals were provided greater PCS scores and subscales than individuals who are less physically active. Across physical activity levels and smoking status, no significant difference in MCS and its subscales was observed. Furthermore, UPF consumption was higher among smokers, men, and low-active subjects.

Significantly higher PCS scores were observed among individuals with higher education than those with lower education. No significant difference was observed between UPF consumption and mental QoL. Physical and mental QoL was higher among employed individuals, with the consumption of UPFs lower among those with higher education and employed status.

Notable interactions were observed between the consumption of UPFs, sex, and occupation on PCS score. PCS scores significantly decreased in women as UPF consumption increased; however, this pattern was not observed in men. Across both sexes, no significant differences in MCS scores were noted across UPF intake tertiles.

UPF intake decreased PCS scores among physically inactive individuals. Once confounding factors were considered in both active and non-active subjects, no association was observed between MCS score and UPF intake.

Among non-smokers and less educated individuals, lower PCS scores were associated with high UPF intake; however, this association was not observed for MCS. In unemployed individuals, high UPF intake was associated with lower PCS and MCS scores.

Study limitations

The current study was conducted in the Middle East and North Africa regions, thus limiting the generalizability of the findings. The association between UPF consumption and HRQoL could vary across different lifestyles and socioeconomic statuses.

Another limitation of the present study is the potential presence of residual or unmeasured confounding factors. Due to the observational nature of the study, causality could also not be established.

Data on other socioeconomic factors such as disposable income, as well as lifestyle factors like alcohol consumption, was also limited. In the future, longitudinal studies are needed to explore the effects of these variables on the association between HRQOL and dietary variables.

Journal reference:

• Hosseinpour-Niazi, S., Niknam, M., Amiri, P., et al. (2024) The association between ultra-processed food consumption and health-related quality of life differs across lifestyle and socioeconomic strata. BMC Public Health 24(1955). doi:10.1186/s12889-024-19351-7