Lifestyle and socioeconomic status affect the health effects of highly processed foods

A recent study published in the journal BMC Public Health evaluates the role of lifestyle and socioeconomic factors on the adverse effects of highly processed foods (UPF) on health-related quality of life (HRQoL).

Education: The relationship between consumption of staple foods and quality of life varies by lifestyle and socioeconomic status.. Image credit: beauty-box / Shutterstock.com

What are UPFs?

UPFs are widely consumed foods with low nutritional value. They are often high in sugar, salt, and unhealthy fats and lack fiber, protein, and micronutrients.

Global consumption of UPFs is increasing, leading to increased rates of obesity and cardiovascular disease, as well as reduced HRQoL. Previous research has established a positive relationship between healthy eating habits and mental and physical health.

Economic and educational factors may contribute to the use of UPFs and modify their impact on HRQoL. Although many previous studies have examined the relationship between these variables in youth, the current study included a population-based cohort of adults.

About education

The current study included 1,766 adults between the ages of 18 and 78 who were part of the Tehran Lipid and Glucose Study. Assessment of study participants’ UPFs and their HRQoL. Social and lifestyle factors, including smoking and exercise, were also reported.

The two dimensions of physical and mental health were analyzed separately, and their associations with the use of the UPF were grouped into tertiles. The model was then extended to understand how lifestyle and economic factors affect this relationship.

What did the results show?

Almost equally divided between the sexes, more than 80% of the study participants were uneducated and current smokers. The mean age of the study group was 39 years. Males had higher physical score (PCS) and mental score (MCS) than females, while smokers had better PCS scores than nonsmokers.

The average use of UPFs was about 12% of the total energy used. High UPF intake was more common among women, younger and unmarried participants, smokers, and those with a lower body mass index (BMI). These people were also more likely to eat more energy, saturated and unsaturated fats, meat, poultry, fish and refined flour.

Unhealthy fats in the diet can contribute to insulin resistance and low-grade inflammation. The subsequent loss of muscle mass can reduce a person’s functional status, promote weakness and disability, as well as increase the risk of fracture, which reduces HRQoL.

Multivariable mean (95% confidence interval) of the relationship between the most consumed food, physical component score (PCS), and mental component score (MCS), stratified by sex, method of life and social conditions. Data were adjusted for age, sex, BMI, and energy expenditure, smoking status, physical activity level, marital status, and education level.

In comparison, consumption of grains, fruits, milk, vegetables and total carbohydrates and proteins decreased with increasing UPF. Previous studies have shown that improved nutrition increases HRQoL among youth with excess BMI; however, recent studies have reported reduced emotional well-being after these interventions. Importantly, these lessons are not useful for adults, as they are aimed at teenagers.

PCS HRQoL scores decreased with higher UPF use, whereas MCS scores were not affected. The negative effect of the introduction of UPF on the number of PCS was not observed in those with good lifestyles and high economic levels, thus showing that these factors can prevent insulin resistance and inflammation.

The relationship between PCS score and UPF use was modified after including factors such as sex and occupation. In women, PCS scores decreased as UPF intake increased.

Significant interactions were observed between this relationship and the presence of smoking, education and physical activity. Smokers, people with low levels of physical activity, as well as people with low levels of education, were more likely to have lower PCS scores with increased UPF use.

Both PCS and MCS scores were reduced among unemployed individuals with higher UPF use. MCS results did not show any other significant differences in terms of lifestyle changes or socioeconomic status.

In one Australian study of older adults, an additional 10 grams of red meat was associated with a 0.4-point reduction in MCS scores. This observation was contradicted by two randomized control trials in which a high-protein diet was not associated with any change in MCS scores. In particular, most of these studies involved higher use of UPFs than the current study.

Other extensive studies have shown that MCS scores are not related to diet quality. In addition, some prospective studies have reported that young women who eat a healthy diet have a higher score of MCS than men with the same dietary habits. Many studies have also shown that unhealthy eating habits are associated with lower MCS scores.

Decisions

Eating a more refined diet was associated with better physical health, particularly among women, with unhealthy lifestyles and lower socioeconomic status..”

Higher socioeconomic status and higher levels of education and income were associated with improved physical HRQoL. Conversely, lifestyle factors such as smoking and low levels of physical activity were associated with poor physical HRQoL. The current study is among the first to report how smoking affects the relationship between HRQoL and UPF intake.

This study highlights the importance of adopting healthy lifestyles and nutrition among women and people with low economic status.