The impact of smartphone app–based interventions on adolescents’ dietary intake: a systematic review and evaluation of equity factor reporting in intervention studies

Abstract Context Adolescence is a critical stage for improving nutrition. The popularity of smartphones makes them an ideal platform for administering interventions to adolescents. A systematic review has yet to assess the impact of smartphone app–based interventions exclusively on adolescents’ dietary intake. Furthermore, despite the impact of equity factors on dietary intake and the claim for mobile health of increased accessibility, there is minimal research on the reporting of equity factors in the evaluation of smartphone app–based nutrition-intervention research. Objectives This systematic review examines the effectiveness of smartphone app–based interventions on adolescents’ dietary intake and the frequency with which equity factors and statistical analyses specific to equity factors are reported in these intervention studies. Data Sources Databases (ie, Scopus, CINAHL, EMBASE, MEDLINE, PsycINFO, ERIC, and Cochrane Central Register for Randomized Control Trials) were searched for studies published from January 2008 to October 2022. Smartphone app–based intervention studies that were nutrition focused, evaluated at least 1 dietary intake variable, and included participants with a mean age between 10 and 19 years were included. All geographic locations were included. Data Extraction and Analysis Study characteristics, intervention results, and reported equity factors were extracted. Because of the heterogeneity of dietary outcomes, findings were reported as a narrative synthesis. Conclusion In total, 3087 studies were retrieved, 14 of which met the inclusion criteria. Eleven studies reported a statistically significant improvement in at least 1 dietary outcome because of the intervention. Reporting of at least 1 equity factor across articles’ Introduction, Methods, Results, and Discussion sections was minimal (n = 5), and statistical analyses specific to equity factors were rare, occurring in only 4 of the 14 included studies. Future interventions should include a measurement of intervention adherence and report the impact of equity factors on the effectiveness and applicability of interventions for equity-deserving groups.