Comparison Of Four Methods Of Dietary Assessment: Food Records Vs. Combined Food Records With Digital Photography

Methods for collecting dietary intakes of free-living individuals have been studied over the past century and there are many limitations. Collection of dietary intakes from individuals is best done in food diary format and researchers have investigated both written and photographic records. The purpose of this study was to add to the body of literature on studies of collecting dietary intakes by comparing written food records (FR), digital food records (DP), written and digital food records combined (FRDP), and digital food records with limited documentation (DPR) to one another and to a known, criterion value. This study included 50 Registered Dietitians (RD) who analyzed four meal sets each set comprised of three meals for calories, macronutrients and fiber. Means for each group of dietitians were compared between subjects to analyze differences between methods. Relative error was the difference of the known value (the weighed record) from the estimated value for calories and macronutrients and absolute error was defined as the mathematical absolute value of the relative error. Relative error was calculated and used to detect bias between methods and absolute error was used to determine accuracy of the methods. The results showed statistically significant differences between the FR and DP groups for carbohydrate and between the FR and DPR groups for fiber. For relative error the only statistically significant value was for the FR method, and for absolute error the only significant difference was for the FR method for protein. The findings of this study suggest that the use of digital photograph records is a viable option for collecting dietary intakes from free-living individuals