Objective This study was aimed to establish a novel method for dietary assessment with instant photography and to evaluate its efficiency.Methods The investigated subjects were asked to have diet separately.All foods for a meal were prepared and put with dishes on a papery tablecloth which was printed with gridline in one centimeter and square outline.The foods in dishes then were photographed in different shooting angle with a digital camera or a smart phone device.All dishes must be put inside background outline which must be shot into camera and appeared in photographs.The remainder foods were also photographically recorded after the meal.The digital image files were then transferred by storage medium or internet to a working group specialized on food quantitative estimation who was assisted with preformed reference food pictures.For an evaluation study,35 sophomores were recruited to be served with a meal of foods accurately weighed before cooking.The meal was photographed in the way described above for image quantification.The sophomores were also interviewed by separate investigators for 24 hour dietary recall.The food consumption was analyzed on bases of classificatory and total summation.Nutrient intake was calculated for each subject from the meal.The values obtained from the dietary recall and the image quantification were compared with values derived from weight method.Estimation difference (d) and estimation difference rate (％d) as well as absolute value of d (D) and ％D were used to show the extent of estimation deviation.Correlation and regression analyses also were carried out on values between weight method and image quantification as well as dietary recall.Results Total 24 kinds of foods including rice,vegetables,fruits,pork,fish and egg,were included in the experimental meal for the evaluation study.Compared to the data from 24 h dietary recall,food weight estimated by image quantification was more correlated with weighed data,and had more concentrated linear distribution (smaller D and standard deviation,P＜0.01 for total and all varieties of foods).Values of almost all the nutrients,including energy,protein,thiamine,ascorbic acid and calcium,calculated based on food weight from image quantification were more close to those of weighed data compared to the 24 h dietary recall (P＜0.01).Conclusion The novel method for dietary assessment with instant photography (image quantification) is more effective than the conventional 24 h dietary recall to obtain food intake values close to weighed data.
dietary surveymethodologydietary assessment with photography24 hour dietary recall
NETL
NSTL
万方数据
维普
