Reliability of a frequency method for assessing vegetable intake using photos among college students: a smart phone approach

Abstract

Objective

To measure the interrater reliability of assessing the frequency of vegetable intake using mobile photos and descriptions.

Design

Repeated measures design.

Setting

A Midwestern university.

Participants

Undergraduate students (N = 165).

Measurable Outcome/Analysis

Number of times each of these vegetable subgroups were consumed daily: dark green vegetables, beans and peas, starchy vegetables, and other vegetables. Analysis: Two raters independently coded meals using mobile photos and descriptions of meals. Cohen κ was calculated to determine interrater reliability.

Results

A value of κ = 0.9 (p < .001) was obtained, indicating an almost perfect agreement between the two raters. Nearly 92% of participants complied with providing photos along with descriptions of their meals.

Conclusions and Implications

A frequency method using mobile photos and descriptions of meals is a reliable strategy to assess vegetable consumption. This frequency method can improve data quality, reduce participant burden, and minimize recall bias in college nutrition programs.

Keywords:

• Mobile photos
• dietary assessment tools
• coding of photos
• mHealth

Acknowledgements

The authors thank Dr. Susan E. Middlestadt, professor emeritus, for her advice on the conceptualization and implementation of the study. The authors acknowledge Rachel Noirot, the Indiana University dining services dietitian, for her advice and help on gathering information about the university dining services and meal plans offered to students. The authors also acknowledge Velarie Ansu and Wyatt Beckman for their assistance in the initial coding of vegetable intake in the study.

Conflict of interest disclosure

The authors have no conflicts of interest to report. The authors confirm that the research presented in this article met the ethical guidelines, including adherence to the legal requirements, of the United States and received approval from the Institutional Review Board of Indiana University-Bloomington.

Data availability statement

Due to the nature of this research, participants of this study did not agree for their data to be shared publicly, so supporting data is not available.

Table 1. Characteristics of participants (N = 165).

Table 2. Interrater reliability for vegetable subgroups for all meals (N = 2148).

Additional information

Funding

This work was supported by a Grant-in-aid of doctoral research award and by the Women & Hi-Tech Organization Graduate Fellowship awarded to Dr. Trishnee Bhurosy for her dissertation study and through research funds from Dr. Susan E. Middlestadt.