Correlates of weight-related self-monitoring application use during emerging adulthood in a population-based sample

This study was designed to examine (1) the types of technologies or other applications (apps) emerging adults use to track their eating, physical activity, or weight; (2) who uses these apps and (3) whether eating and weight-related concerns during adolescence predict app use in emerging adulthood.

Longitudinal survey data were obtained from EAT 2010-2018 (Eating and Activity over Time study, N = 1428), a population-based sample of ethnically/racially and socioeconomically diverse adolescents (mean age: 14.5 ± 2.0 years), who were followed into emerging adulthood (mean age: 22.0 ± 2.0 years). Data were used to examine sociodemographic correlates of physical activity- and dietary-focused app use. Adjusted, gender-stratified logistic regressions were used to investigate longitudinal relationships between eating and weight-related concerns in adolescence and app use in emerging adulthood.

Compared to men, women were more likely to use physical activity- (23.2 versus 12.5%, p < 0.001) and dietary-focused apps (16.1 versus 5.5%, p < 0.001). Among women, eating and weight-related concerns in adolescence, particularly unhealthy muscle-building behaviors (OR = 1.73, 95% CI 1.03-2.92), were associated with later dietary-focused app use. Among men, use of other muscle-building behaviors and body dissatisfaction in adolescence predicted use of physical activity- (OR_{other muscle-building} = 1.60, 95% CI 1.03-2.49 and OR_{body dissatisfaction} = 1.67, 95% CI 1.06-2.65) and dietary-focused (OR_{other muscle-building} = 2.18, 95% CI 1.07-4.47 and OR_{body dissatisfaction} = 2.35, 95% CI 1.12-4.92) apps 8 years later.

Eating and weight-related concerns may predict later use of physical activity- and dietary-focused apps; future research is needed to understand whether use of such apps further increases eating and weight-related concerns.

III, well-designed longitudinal cohort study.