Validity and Reliability of Photographic Diet Diaries for Assessing Dietary Intake Among Young Children

Abstract

Obtaining valid, reliable dietary intake data for young children is challenging. The objective of this study was to assess the validity, reliability, and acceptability of the addition of photography to traditional written diet diaries for recording young children's dietary intake. Twenty-two parents of preschoolers enrolled to complete a 2-day photographic diet diary for their child. Diaries were coded by a trained nursing student for food weight, calories, and macronutrients. A random sample of diaries was evaluated by an independent nutritionist to determine interrater reliability. Convergent validity was tested by comparing visual estimates and actual values of photos of 24 researcher-created meals/snacks. Acceptability was assessed through participants' feedback, completion rates for the project, project costs, and quality of the data obtained. Reliability was assessed by computing intraclass correlations between caloric and macronutrient data from 2 independent diary evaluators. Convergent validity was assessed by calculating intraclass correlations between visually estimated photo diary evaluations and actual premeasured researcher-created meals/snacks. Medium to large correlations between the 2 independent evaluators (.51-.63) were found for caloric and macronutrient values, with the exception of protein (r = –.21). Strong correlations (food served, r = .69-.96; food consumed, r = .66-.83) were obtained between visual estimates and actual values of calories and macronutrients for the premeasured foods. Preliminary results indicate the addition of photographs to a traditional diet diary may enhance the validity and reliability of prospective dietary intake recording. Parents and children indicated the activity was fun, and quality data resulted, indicating that this method is acceptable.