Evaluation of a mobile telephone food record for adults and adolescents
Abstract
The development of a mobile telephone food record (mpFR) has the potential to improve the accuracy of dietary assessment by reducing burden on the respondent and researcher. Respondents use the mpFR to capture images of foods and beverages before and after eating. Methods of image analysis allow for automatic food identification and portion size estimation. To obtain an image suitable for image analysis, all foods and beverages and a fiducial marker must be included. The information from image analysis and portion size estimation can be indexed with the Food and Nutrient Database for Dietary Studies (FNDDS) to estimate nutrient intakes. The objectives of this thesis were to evaluate the usability of the mpFR among adolescents and adults, and to evaluate the FNDDS for use with the mpFR. Adults and adolescents were recruited to use the mpFR under controlled conditions, capture images of foods and beverages, and provide their perceptions and preferences. All adults and a majority of the adolescents (78%) were able to include all foods and beverages, but inclusion of the fiducial marker proved more problematic. Compared to adolescents, significantly more adults had to capture more than one image before (P<0.05) and after (P<0.01) their first meal session to obtain an image suitable for image analysis. A majority of both age groups (91% adults, 79% adolescents) agreed that the mpFR software was easy to use; however, additional interactive training will likely be necessary for all users to provide extra practice before entering a free-living situation. To evaluate the FNDDS, foods selected for a controlled feeding study were matched to food codes in the FNDDS 3.0 to estimate energy and protein content. The energy and protein contents of these foods were also measured using a bomb calorimeter and Dumas nitrogen analyzer, respectively. The measured energy and protein values correlated significantly with the energy (r=0.981, P<0.01) and protein (r= 0.911, P<0.01) values in the FNDDS, supporting use of the FNDDS with the mpFR. Improved accuracy in the dietary intake data obtained with the mpFR may help strengthen relationships between diet and chronic diseases and delineate the mechanisms of gene-nutrient interactions.
Degree
M.S.
Advisors
Boushey, Purdue University.
Subject Area
Nutrition|Epidemiology
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