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Validation Information: Remote Food Photography Method (RFPM)

Martin 2012

Validity of the Remote Food Photography Method (RFPM) for Estimating Energy and Nutrient Intake in Near Real-Time

Two studies "are reported; a pilot study to demonstrate feasibility followed by a larger validity study. Study 1’s objective was to test the effect of two ecological momentary assessment (EMA) approaches that varied in intensity on the validity/accuracy of estimating energy intake (EI) with the Remote Food Photography Method (RFPM) over 6 days in free-living conditions. When using the RFPM, Smartphones are used to capture images of food selection and plate waste and to send the images to a server for food intake estimation. Consistent with EMA, prompts are sent to the Smartphones reminding participants to capture food images. During Study 1, EI estimated with the RFPM and the gold standard, doubly labelled water (DLW), were compared. Participants were assigned to receive Standard EMA.

Prompts (n = 24) or Customized Prompts (n = 16) (the latter received more reminders delivered at personalized meal times). The RFPM differed significantly from DLW at estimating EI when Standard (mean ± s.d. = −895 ± 770 kcal/day, P < 0.0001), but not Customized Prompts (−270 ± 748 kcal/day, P = 0.22) were used. Error (EI from the RFPM minus that from DLW) was significantly smaller with Customized vs. Standard Prompts. The objectives of Study 2 included testing the RFPM’s ability to accurately estimate EI in free-living adults (N = 50) over 6 days, and energy and nutrient intake in laboratory-based meals. The RFPM did not differ significantly from DLW at estimating free-living EI (−152 ± 694 kcal/day, P = 0.16). During laboratory-based meals, estimating energy and macronutrient intake with the RFPM did not differ significantly compared to directly weighed intake</p

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Validation Information

Year of Publication

Tool Information

Dietary Exposure Measured
Full Nutrient
Tool Type
Food Diary Estimated
Timeframe Tool Measures info
6 days
Portion Size Measures info
Portion sizes were estimated by trained registered dieticians using the photographs provided
Reporting Method info
Format info
Supplements Measured
Not reported
Administration Method info
Self administered (includes prompts to take photographs)

Study Information

Study Location
Associated Nutrient Database
The tool uses the Food and Nutrient Database for Dietary Studies 3.0
Comparator Validated Against
Doubly Labelled Water, Other


Sample Size
42 (Doubly Labelled Water), 49 (Laboratory-based buffet meals)
Age of Population

Mean (SD): 41 (12.8) years

Other Notable Characteristics
88% of subjects were female, 62% were White and 38% were African American. Only results reported from study 2 (validation of nutrients) are summarised here.

Total number of nutrients validated: 10 info

Not all of the nutrients validated in the validation studies are included in the table below, as statistical data was only selected to be displayed for a number of nutrients, this included:

  • Energy
  • Fat
  • Saturated Fat
  • Mono-unsaturated Fat
  • Poly-unsaturated Fat
  • Carbohydrates
  • Protein
  • Sugar
  • Non‐starch polysaccharides(NSP)
  • Sodium
  • Calcium
  • Iron
  • Zinc
  • Retinol
  • Folate
  • Folic Acid
  • Vitamin B12
  • Vitamin C
  • Fruit & Vegetables
  • Urinary Nitrogen

To find information on the other validated nutrients please read the validation study.

  • Energy
  • Macronutrients: 4
  • Micronutrients: 6
Comparator Lifestage Sex Nutrient Measured info Mean Difference Standard Deviation info Correlation Coefficient info Cohen's Kappa Coefficient Percentage Agreement Percentage Agreement Categories info Lower Limits of Agreement Upper Limits of Agreement
Doubly Labelled Water Adults Both
Laboratory-based buffet meals (quantified by weighing food provision and waste) Adults Both

Some results have been calculated using statistical techniques based on the published data.

For further information on statistical terms click on Statistical tests used in validation studies

All correlations coefficients in the table are unadjusted unless stated otherwise. For adjusted correlation coefficients and other statistical methods used in the study e.g. paired t-tests, please read the validation articles.

  • # Adjusted
  • † Energy adjusted.
  • ‡ For loge-transformed, energy-adjusted nutrient intakes.
  • ^ Adjacent included.
  • ᵟ Participants provided identical responses.
  • (w) = Weighted.

Martin CK, Correa JB, Han H, Allen HR, Rood JC, Champagne CM, Gunturk BK, Bray GA. Validity of the Remote Food Photography Method (Rfpm) for Estimating Energy and Nutrient Intake in near Real‐Time. Obesity. 2012 Apr 1;20(4):891-9.