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

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.