Workshop 1: Use of technology in dietary assessment

Abstract

A breakout session focusing on the use of technology in dietary assessment involved attendees posing a series of questions and making several observations in relation to an earlier presentation on the ‘Use of technology in children’s dietary assessment’. 1. The first issue discussed related back to a slide showing the process of image segmentation and estimation of food volume. Using computer software, image calibration and image segmentation allow for the volume of food on a person’s plate to be calculated. However, testing has shown that this procedure is not always accurate. Shadows created by a food item sitting on a plate make the object appear larger than it really is. It is hoped that, in time and with further development of the software, the volume of food eaten by individuals will improve dietary assessment studies. Weight, as opposed to volume, is used to estimate the edible portion of a food item with the portion size of an apple, for example, coded as small, medium or large, and either peeled or cored. Estimation of food volume should help avoid the approximations presently involved in determining daily energy and nutrient intakes and provide a more accurate quantification of the edible portion of a food. 2. Mobile hand-held devices have evolved to function as computers, and many now comprise a camera. Potentially, this makes them ideal tools to use in dietary assessment surveys. Results from pilot studies have shown good compliance rates among participants who were asked to take images of their food using hand-held devices (that is, camera-PDA devices). When asked to use a disposable camera, adolescents willingly took more pictures of the food they were eating than was requested. Successful development of hand-held devices should enable study participants to create a record of their food consumption over the day. The images will be stored in the hand-held devices before being sent to a central computer. Importantly, it should be possible to match the images of foods with their nutrient composition using any of the available nutrient databases.