JMIR Publications

ABSTRACT

Background:

Childhood obesity is a major global public health concern, yet many parent-focused mobile health interventions lack cultural tailoring, theoretical grounding, and transparent formative evaluation. MyKidsFit is a culturally tailored, theory-informed parenting app developed to support Korean parents in promoting healthy lifestyle behaviors for children at risk of obesity.

Objective:

This study aimed to describe the iterative, user-centered development of MyKidsFit based on the Information–Motivation–Behavioral Skills (IMB) model and Korean cultural context, and to evaluate its preliminary feasibility, usability, content validity, and acceptability before efficacy testing.

Methods:

A sequential exploratory mixed-methods design was used across three phases. Phase 1 involved IMB-based app development and iterative prototype refinement from January to June 2024. Phase 2 included semi-structured interviews with six Korean mothers conducted in July 2024. Data were analyzed using conventional content analysis, with member checking performed and interrater reliability confirmed. Findings from Phase 2 informed subsequent app modifications. In Phase 3, six parents and seven experts evaluated the app using a structured 15-item questionnaire assessing informational, motivational, behavioral, and design-related domains. The questionnaire demonstrated excellent content validity (CVI=1.0) and internal consistency (Cronbach α=0.93).

Results:

Three rounds of iterative revisions were conducted to improve menu structure, content clarity, and cultural relevance of dietary examples. Parents and experts reported high ratings for app usability, educational appropriateness, motivational features, and behavioral skills support, with mean item scores ranging from 3.3 to 4.0 out of 4. Overall satisfaction scores were high among both parents (mean 91.2, SD 7.57) and experts (mean 90.7, SD 3.45). Qualitative feedback highlighted the usefulness of culturally relevant dietary guidance, weekly challenges, reward systems, and family-centered interaction features. Findings represent formative evaluation focused on developmental feasibility and acceptability rather than clinical effectiveness.

Conclusions:

MyKidsFit demonstrated preliminary feasibility, usability, content validity, and acceptability through a transparent iterative development process. These findings provide foundational support for future randomized controlled trials evaluating the app’s effects on parenting practices and child health-related behaviors. Clinical efficacy cannot be inferred from the present study.