Accepted for/Published in: JMIR Human Factors
Date Submitted: Jul 30, 2025
Date Accepted: Jun 17, 2026
Warning: This is an author submission that is not peer-reviewed or edited. Preprints - unless they show as "accepted" - should not be relied on to guide clinical practice or health-related behavior and should not be reported in news media as established information.
Design and Intervention of a Smart Phone App to Improve Intuitive Eating and Diet Quality
ABSTRACT
Background:
Web-based and mobile phone-based applications have become widely available for dietary self-monitoring; however, their use may increase risk of disordered eating. College students frequently demonstrate poor nutrient intake despite consumption of sufficient calories. One way to improve diet quality may be via use of a smart phone app which encourages intuitive eating.
Objective:
The purpose of this study was to build and assess a smart phone application (app) designed to promote intuitive eating and improve diet quality among college-age users.
Methods:
The In2Eat iOS mobile app was developed in SwiftUI and stored user data in a Firebase database. 45 college students completed assessments of intuitive eating, diet quality, and disordered eating before and after four weeks of using the In2Eat app. Users evaluated use of the app with the system usability scale. Engagement with the app was recorded as the total number of days a meal was logged, the total number of meals logged, and the average number of meals logged per day.
Results:
The average system usability score for the In2Eat app was 67.2 (SD 15.5). The number of days a meal was logged was positively correlated with system usability scores (r=.28, P=.06), and the total number of meals logged had a monotonic association with app usability (ρ=.31, P=.04). When divided according to low (10.2±5.3), medium (26.3±2.8), and high (33.6±3.8) number of days logging meals, participants with higher days of logging reported the app as more usable (H=6.75, P=.03). A regression analysis showed that 8% of the variance in system usability (R²=.080, P=.31) was explained by app use; however, none of the individual predictors were statistically significant. Global intuitive eating did not change during the user study; however, the unconditional permission to eat subscale increased (3.60±1.03 vs. 3.87±0.92, P=.01). Overall disordered eating also did not change with app use, although dietary restraint decreased (0.99±1.39 vs. 0.66±1.05, P=.03). Dietary qualities which protect against chronic disease increased 28%, fruit consumption increased 63%, and skin antioxidant levels increased 6.1% (15.38±1.90 vs. 15.71±2.04, P=.03).
Conclusions:
Results suggest that participants who logged more meals tended to rate the app as more usable. A smart phone app can be used to promote intuitive eating and improve diet quality without increasing disordered eating. Further research is needed with a greater sample size after incorporating features to improve the app’s usability.
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