title: A novel method to remotely measure food intake of free-living individuals in real time: the remote food photography method.
abstract: The aim of the present study was to report the first reliability and validity tests of the remote food photography method (RFPM), which consists of camera-enabled cell phones with data transfer capability. Participants take and transmit photographs of food selection and plate waste to researchers/clinicians for analysis. Following two pilot studies, adult participants (n 52; BMI 20-35 kg/m2 inclusive) were randomly assigned to the dine-in or take-out group. Energy intake (EI) was measured for 3 d. The dine-in group ate lunch and dinner in the laboratory. The take-out group ate lunch in the laboratory and dinner in free-living conditions (participants received a cooler with pre-weighed food that they returned the following morning). EI was measured with the RFPM and by directly weighing foods. The RFPM was tested in laboratory and free-living conditions. Reliability was tested over 3 d and validity was tested by comparing directly weighed EI to EI estimated with the RFPM using Bland-Altman analysis. The RFPM produced reliable EI estimates over 3 d in laboratory (r 0.62; P < 0.0001) and free-living (r 0.68; P < 0.0001) conditions. Weighed EI correlated highly with EI estimated with the RFPM in laboratory and free-living conditions (r>0.93; P < 0.0001). In two laboratory-based validity tests, the RFPM underestimated EI by - 4.7 % (P = 0.046) and - 5.5 % (P = 0.076). In free-living conditions, the RFPM underestimated EI by - 6.6 % (P = 0.017). Bias did not differ by body weight or age. The RFPM is a promising new method for accurately measuring the EI of free-living individuals. Error associated with the method is small compared with self-report methods.
authors.affiliation: Pennington Biomedical Research Center, 6400 Perkins Road, Baton Rouge, LA 70808, USA. Corby.Martin@pbrc.edu
authors.forename: Corby K
authors.initials: CK
authors.lastname: Martin
authors.forename: Hongmei
authors.initials: H
authors.lastname: Han
authors.forename: Sandra M
authors.initials: SM
authors.lastname: Coulon
authors.forename: H Raymond
authors.initials: HR
authors.lastname: Allen
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Champagne
authors.forename: Stephen D
authors.initials: SD
authors.lastname: Anton
mesh_terms: D000293:Adolescent; D000328:Adult; D004034:Diet Surveys; D004046:Dietetics / Q000379:methods*; D004435:Eating; D005260:Female; D005518:Food Preferences; D006801:Humans; D020407:Internet; D008297:Male; D008875:Middle Aged; D010781:Photography; D010865:Pilot Projects; D015203:Reproducibility of Results