A mobile health intervention shows no significant short-term effects on diet, growth, or lipid profiles in Amazonian schoolchildren: a randomized controlled trial.

Abstract

Background: Diet quality among Amazonian children has declined, driven by erosion of traditional food cultures and limited access to nutrition education in remote regions.

Objectives: To evaluate the efficacy of a mobile health (mHealth) intervention in improving dietary patterns, growth, and lipid profiles among school-aged children in the Brazilian Amazon.

Methods: In a randomized controlled trial, 266 caregivers were assigned to receive 19 weeks of standardized multimedia messages (intervention group, IG) or usual care (control group, CG). The primary outcome was change in BMI-for-age z scores. Secondary outcomes were dietary intake and serum lipid concentrations. Analyses followed intention-to-treat and per-protocol principles using paired and unpaired t tests, chi-square tests, and group-by-time interaction analysis.

Results: In the intention-to-treat analysis, BMI-for-age decreased significantly within the CG (mean change: -0.10; 95% CI: -0.17, -0.03), particularly among boys (mean change: -0.17; 95% CI: -0.30, -0.05), but between-group differences were not significant. In the per-protocol analysis, boys in the CG had lower BMI-for-age than those in the IG (difference: 0.25; 95% CI: 0.01, 0.50). Both groups exhibited within-group reductions in ultra-processed food (UPF) consumption (IG median change: -1.31; 95% CI: -1.90, -0.76; CG: -1.19; 95% CI: -1.80, -0.60) and improvements in total and LDL cholesterol. Group-by-time interaction analysis showed no significant intervention effects beyond time-related changes.

Conclusions: The mHealth intervention yielded no significant effects beyond usual care. Nonetheless, reductions in UPF intake observed in both groups highlight the potential of mobile messaging as a complementary approach to promote healthy eating in remote Amazonian populations.

Clinical trial registry number and source website: Brazilian Clinical Trials Registry (RBR-5zdnw6t) STATEMENT OF SIGNIFICANCE: This study provides fresh evidence on the feasibility and potential impact of a low-cost mobile health (mHealth) intervention to promote healthier dietary behaviors, support adequate growth, and improve lipid profiles among school-aged children in a remote Amazonian setting. In the context of rising ultra-processed food consumption and limited access to nutrition services, delivering culturally tailored multimedia messages to caregivers represents a scalable and context-appropriate approach to mitigate diet-related health risks in vulnerable populations. These findings contribute to the growing body of evidence supporting digital nutrition interventions in resource-limited and geographically isolated regions.