Weight loss apps were evaluated for their use of four behavior change theories: Transtheoretical Model, Social Cognitive Theory, The Theory of Planned Behavior and The Health Belief Model. A previously validated template was used to evaluate the apps. It included 20 theoretical constructs reflective of the four theories and evaluated each at five levels of interaction, to create a 100-point scale. Two researchers independently coded each app. Descriptive features of each app were also collected. The data was analyzed using frequencies, mean scores, and regression analysis. Over 1600 apps were retrieved; of these, 74 apps met the inclusion criteria for evaluation. Most (51.4%) of the apps were free. A third of the apps (33.8%) were rated highly by users. Most apps (73%) offered a food log, (52.7%) an exercise log, and (74.3%) a weight tracker. Only 20.3% were affiliated with an established organization and 25.7% were created by a health expert. Theory scores ranged from 3 to 47; the mean score was 9.8 (SD=7.8). The Health Belief Model was used most frequently (12.5%), while the Transtheoretical Model was least used (10.3%). Variables that were significant or marginally significant predictors for theory score were those that had higher ratings (p=.089), were affiliated with organizations (p=.001) and were created by a health expert (p=.015). In multivariable regression, only affiliation remained a significant (p=.02) predictor of theory score. Overall, weight loss apps are lacking a foundation of behavioral theory. They currently do a better job of providing general information, individualized calorie goals and formats to log food and exercise. Results of this research can serve to strengthen the dialogue between healthcare practitioners and app creators.
Presentation: 21 minutes
Recommended CitationPorter, Michelle, "Weight Loss Apps: To What Extent Are They Grounded in Behavior Change Theory?" (2013). Master of Public Health Thesis and Capstone Presentations. Presentation 96.