Date of Award


Document Type


Degree Name

Master of Science (MS)


College of Education and Human Services


Nutrition and Food Studies

Thesis Sponsor/Dissertation Chair/Project Chair

Shahla Wunderlich

Committee Member

Yeon Bai

Committee Member

Mousumi Bose


Mobile weight loss applications (‘apps’) such as MyFitnessPal® and Lose It!® have millions of downloads and allow users to track their intake on the go by accessing a massive digital nutrition database, and while the apps have been successful tools for participants in structured weight loss initiatives, little research has explored their efficacy for stand-alone users. The aim of this study was to examine the role of user adherence behavior, portion estimation and consumption norms, and the potential for the app to act as a behavior change tool. An online survey was administered to individuals 18 years or older who have used either MyFitnessPal or Loselt! in order to assess frequency of use, completeness of food records, portion estimation ability, portion consumption norms, and qualitative feedback on factors that impact user experience. Data was gathered using Qualtrics Survey Software and analyzed in IBM SPSS Statistics 22.0 using correlations, t-tests, ANOVA, ANCOYA, and linear regressions. Qualitative data was analyzed through coding and emergence of themes. Fully adherent groups lost significantly more weight than less adherent groups when controlling for duration of usage, and overall, adherence and duration predicted 40% of Average Total Completeness (p<0.01). Participants displayed poor estimation skills, overestimating portion size by an average of 77.54%. Portion norms were not significantly related to weight loss but were positively related to Portion Estimation Error (p<0.01). Qualitative analysis revealed four major themes that influence and explain user experience: App Features, App Qualities, Social Components, and the App as a Behavior Change Tool. Overall, these findings indicate that apps have the potential to be highly effective methods of behavior modification for those looking to lose weight, and strict adherence improves weight loss. Findings also suggest that there is a need for portion education and estimation assistance for users.

File Format


Included in

Nutrition Commons