title: Design and usability evaluation of user-centered and visual-based aids for dietary food measurement on mobile devices in a randomized controlled trial.
abstract: We designed and developed two interactive apps interfaces for dietary food measurements on mobile devices. The user-centered designs of both the IPI (interactive photo interface) and the SBI (sketching-based interface) were evaluated. Four types of outcomes were assessed to evaluate the usability of mobile devices for dietary measurements, including accuracy, absolute weight differences, and the response time to determine the efficacy of food measurements.
  
  
  
  The IPI presented users with images of pre-determined portion sizes of a specific food and allowed users to scan and then select the most representative image matching the food that they were measuring. The SBI required users to relate the food shape to a readily available comparator (e.g., credit card) and scribble to shade in the appropriate area. A randomized controlled trial was conducted to evaluate their usability.
  
  
  
  A total of 108 participants were randomly assigned into the following three groups: the IPI (n=36) and SBI (n=38) experimental groups and the traditional life-size photo (TLP) group as the control. A total of 18 types of food items with 3-4 different weights were randomly selected for assessment by each type. The independent Chi-square test and t-test were performed for the dichotomous and continuous variable analyses, respectively. The total accuracy rates were 66.98%, 44.15%, and 72.06% for the IPI, SBI, and TLP, respectively. No significant difference was observed between the IPI and TLP, regardless of the accuracy proportion or weight differences. The SBI accuracy rates were significantly lower than the IPI and TLP accuracy rates, especially for several spooned, square cube, and sliced pie food items. The time needed to complete the operation assessment by the user was significantly lower for the IPI than for the SBI.
  
  
  
  Our study corroborates that the user-centered visual-based design of the IPI on a mobile device is comparable the TLP in terms of the usability for dietary food measurements. However, improvements are needed because both the IPI and TLP accuracies associated with some food shapes were lower than 60%. The SBI is not yet a viable aid. This innovative alternative required further improvements to the user interface.
authors.affiliation: Department of Industrial Design, College of Management, Chang Gung University, Taoyuan, Taiwan; Internal Medicine, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Electronic address: ycl30@mail.cgu.edu.tw.
authors.forename: Ying-Chieh
authors.initials: YC
authors.lastname: Liu
authors.affiliation: CyberTrust Technology Institute, Institute for Information Industry, Taipei, Taiwan. Electronic address: marken@iii.org.tw.
authors.forename: Chien-Hung
authors.initials: CH
authors.lastname: Chen
authors.affiliation: Department of Industrial Design, College of Management, Chang Gung University, Taoyuan, Taiwan. Electronic address: s923446@gmail.com.
authors.forename: Chien-Wei
authors.initials: CW
authors.lastname: Lee
authors.affiliation: Internal Medicine/Health Promotion Center, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Electronic address: ma3958@cgmh.org.tw.
authors.forename: Yu-Sheng
authors.initials: YS
authors.lastname: Lin
authors.affiliation: Department of Nutrition Therapy, Chang Gung Memorial Hospital, Taoyuan, Taiwan. Electronic address: yun0726@cgmh.org.tw.
authors.forename: Hsin-Yun
authors.initials: HY
authors.lastname: Chen
authors.affiliation: Department of Health Care Management and Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan. Electronic address: yellow@mail.cgu.edu.tw.
authors.forename: Jou-Yin
authors.initials: JY
authors.lastname: Yeh
authors.affiliation: Department of Health Care Management and Healthy Aging Research Center, Chang Gung University, Taoyuan, Taiwan; Division of Hepatogastroenterology, Department of Internal Medicine, Kaohsiung Chang Gung Memorial Hospital, Kaohsiung, Taiwan. Electronic address: sherrychiu@mail.cgu.edu.tw.
authors.forename: Sherry Yueh-Hsia
authors.initials: SY
authors.lastname: Chiu
mesh_terms: D000328:Adult; D001835:Body Weight; D040421:Cell Phone; D004032:Diet; D015930:Diet Records; D005260:Female; D006801:Humans; D008297:Male; D063731:Mobile Applications; D014584:User-Computer Interface; D055815:Young Adult
keywords: Food measurement; Interactive apps; Randomized controlled trial; Usability; User-centered design