Author: Chung, Ming-yan Louisa
Title: Development of interactive dietary intake portal with digital images
Degree: DHSc
Year: 2009
Subject: Hong Kong Polytechnic University -- Dissertations.
Food habits -- China -- Hong Kong.
Web portals -- China -- Hong Kong.
Department: Department of Applied Social Sciences
Pages: xiv, 192 leaves : col. ill. ; 30 cm.
Language: English
Abstract: Background: Dietary recording is important, but contemporary dietary recording methods are not user-friendly. New concepts in information technology have been applied to solve some of the existing issues. Previous studies of two-dimensional (2D) food images have found them to be reliable for portion size estimations. However, they are unable to facilitate volume estimation and estimations of ingredients, sauce type, amount of oil added and cooking methods, all of which affect the final calculation of calories. It is therefore necessary to investigate these images and determine whether three-dimensional (3D) images are better for volume estimations. In addition, a usability test was carried out on the new portal developed to test its user acceptance. Objectives: To develop an interactive dietary intake portal with digital images and to test its usability. Method: The study comprised four stages. Stage 1 identified the 10 food items most frequently consumed by the Hong Kong population. Stage 2 used the food items identified as the test items and captured them in 2D and 3D images. The volume, ingredients, added oil, cooking method and sauce type of the items were estimated by 10 observers. With the results obtained, an interactive dietary intake portal (the Portal) was developed in Stage 3 and then tested for usability in Stage 4. Results: The 10 most frequently consumed food items identified were white rice (n = 33), steamed chicken (n = 15), leafy vegetables (n = 34), milk (n = 8), steamed fish (n = 19), dumplings (n = 6), oranges (n = 8), Chinese soup (n = 13), a combination of toast (n = 3), sausage (n = 2) and egg (n = 2), and potato chips (n = 4). The agreement on ingredients was similar for both 2D and 3D images, but the 2D images were slightly better for cooking methods and the 3D images slightly better for sauce type. The ICCs were high for both types of images (2D: ICC = 0.916, p < 0.001; 3D: ICC = 0.846, p < 0.001). The one-sample t-test found that using 2D or 3D food images was reliable for food volume estimations, but not for oil amount. High mean average scores were also obtained in the three usability domains for the Portal ("System Use" = 2.60, "Information Quality" = 2.75, "Interface Quality" = 3.05). Discussion: The comparison between 2D and 3D images indicated 3D images having strengths in the area of smaller observer variances and higher accuracy in sauce type identification, although not all tested aspects. The application of 2D food images in the development of the Portal is taken into the consideration that 2D images are easier for users to capture and require less storage in the database. It is the first of its kind in the nutrition discipline. It is a ready-to-use instrument that can be applied clinically. It will also encourage the continuity of dietary recording and can thus benefit large-scale research. Conclusion: An interactive dietary intake portal with reliable digital food images for accurate food evaluations was developed.
Rights: All rights reserved
Access: restricted access

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