Background and Objective:

An unhealthy lifestyle, including poor diet and the increasing consumption of ultra-processed foods (UPF), is linked to obesity, metabolic alterations, and systemic blood pressure changes. The objective of this study is to investigate the influence of UPF consumption, evaluated through dietary markers, on systolic (SBP) and diastolic (DBP) blood pressure in children with obesity.

Methods:

Longitudinal analysis of a randomized clinical trial conducted with children aged 7 to 12 years old who had obesity. For six months, children and their guardians participated in individual consultations and monthly educational actions to encourage the reduction of UPF consumption. Body weight, height, blood pressure and 24-hour dietary recalls were measured at all visits. A total of 96 children with at least one blood pressure measurement in the follow-up, were included in the analysis out of 101 children in the study. Spot urine samples were collected at the beginning of the study, in the second and fifth months of follow-up.

Results:

Energy intake, UPF consumption, and blood pressure showed a quadratic pattern of change, with a decrease in the first two months and an increase thereafter. There was an association between UPF consumption and DBP. UPF intake was correlated with urinary sodium/potassium (Na/K) ratio (r=0.29; p=0.008) and dietary Na/K ratio (r=0.40; p<0.001). For every 100g increase in UPF, DBP increased by 0.28mmHg (p-value=0.01), and with additional adjustment for change in body mass index (BMI) and physical activity, the increase was 0.22mmHg.

Conclusion:

Our findings indicate that consuming less UPF may have an impact on blood pressure in children with obesity. Additional adjustment for BMI and physical activity did not influence the results. Therefore, reducing UPF consumption may be a strategy against hypertension.