Abstract A16: Use of a smartphone application for weight loss versus a paper-based dietary diary: A randomized trial
Authors: Ahn Jeong Sun , Lee Heejin , Kim Jiae , Park Haemin , Kim Dong Woo , Lee Jung Eun 
Published: June 2022

Abstract
Objectives: The World Health Organization (WHO) announced in 2018 that one-third of deaths from cancer are due to dietary and behavioral risks including high body mass index, low fruit and vegetable intake, lack of physical activity, tobacco use, and alcohol use. Therefore, effective intervention strategies to maintain a balanced diet and healthy weight are needed to reduce the burden of cancer. There is increasing evidence that mobile health (mHealth) tools have value in dietary monitoring and assessment. This study aims to evaluate the effectiveness of the smartphone application (app) for weight loss versus a paper-based dietary diary among adults with a body mass index (BMI) of 23 kg/m2 or above.
Methods: A total of 33 men and 17 women aged 18-39 years participated in a six-week randomized trial. We randomly assigned participants to one of two groups: (A) smartphone app group (n=25) or (B) paper-based diary group (n=25). The smartphone app group recorded foods and dietary supplements that they consumed and received immediate dietary feedback using “Well-D”—a self-dietary monitoring app developed by our team. The paper-diary group was instructed to record foods or supplements that they consumed using the self-recorded diary. The primary outcomes were weight, BMI, and waist circumference. We also examined changes in nutrient intakes including energy, carbohydrate, protein, fat, dietary fiber, vitamins, and minerals using 3-day 24-hour recalls (24HR) across time at pre- and post-intervention. Differences between pre- and post-interventions within each group were compared using a paired t-test or Wilcoxon signed rank test. Differences in changes between the two groups were analyzed using an independent t-test.
Results: Body weight, BMI, and waist circumference were not significantly different between the app group and paper-diary group (p&gt;0.2). We observed a significant decrease in BMI in the paper-diary group (p=0.02) but not in the Well-D group (p=0.26) upon comparing pre-intervention anthropometric measures with the post-intervention measures. The waist circumferences decreased significantly in both groups (p&lt;0.01). The caloric intake decreased from pre- to post-intervention in both groups (p=0.04 for the Well-D group and p=0.06 for the paper-diary group). However, the changes in nutrient intakes were not statistically significant between the two groups.
Conclusions: There were no differences in body weight, BMI, waist circumference, and nutrient intakes between the app group and the paper-diary group. Body weight and BMI were reduced from pre- to post-intervention in the paper-diary group and waist circumference was reduced in both groups.
Funding: This research was supported by the MSIT (Ministry of Science and ICT), Korea, under the ITRC (Information Technology Research Center) support program (IITP-2018-2014-1-00720) supervised by the IITP (Institute for Information & Communications Technology Promotion).
Citation Format: Jeong Sun Ahn, Heejin Lee, Jiae Kim, Haemin Park, Dong Woo Kim, Jung Eun Lee. Use of a smartphone application for weight loss versus a paper-based dietary diary: A randomized trial [abstract]. In: Proceedings of the AACR Special Conference on Modernizing Population Sciences in the Digital Age; 2019 Feb 19-22; San Diego, CA. Philadelphia (PA): AACR; Cancer Epidemiol Biomarkers Prev 2020;29(9 Suppl):Abstract nr A16.