Accuracy of a Web-Based Time-Use Diary (MEDAL) in Assessing Children’s Meal Intakes With Food Photography by Parents as Reference: Instrument Validation Study

Abstract

Background My E-Diary for Activities and Lifestyle (MEDAL) is a web-based time-use diary developed to assess the diet and movement behaviors of Asian school children. Objective This study aims to determine the accuracy of MEDAL in assessing the dietary intake of Malaysian school children, using photographs of the children’s meals taken by their parents as an objective reference. Methods A convenience sample of 46 children aged 10 to 11 years recorded their daily meals in MEDAL for 4 days (2 weekdays and 2 weekend days). Their parents took photographs of the meals and snacks of their children before and after consumption during the 4-day period and sent them along with a brief description of food and drinks consumed via an instant SMS text messaging app. The accuracy of the children’s reports of the food they had consumed was determined by comparing their MEDAL reports to the photographs of the food sent by their parents. Results Overall, the match, omission, and intrusion rates were 62% (IQR 46%-86%), 39% (IQR 16%-55%), and 20% (IQR 6%-44%), respectively. Carbohydrate-based items from the food categories “rice and porridge”; “breads, spreads, and cereals”; and “noodles, pasta, and potatoes” were reported most accurately (total match rates: 68%-76%). “Snack and dessert” items were omitted most often (omission rate: 54%). Furthermore, side dishes from “vegetables and mushrooms,” “eggs and tofu,” “meat and fish,” and “curry” food groups were often omitted (omission rates: 42%-46%). Items from “milk, cheese, and yogurt”; “snacks and desserts”; and “drinks” food groups intruded most often (intrusion rates: 37%-46%). Compared to the items reported by the boys, those reported by the girls had higher match rates (69% vs 53%) and lesser omission rates (31% vs 49%; P=.03, respectively). Conclusions In conclusion, children aged 10 to 11 years can self-report all their meals in MEDAL, although some items are omitted or intruded. Therefore, MEDAL is a tool that can be used to assess the dietary intake of Malaysian school children.