Can a Web-based food record accurately assess energy intake in overweight and obese women? A pilot study

Innovative dietary intake measurement tools, such as web-based food records, are becoming increasingly available for self-monitoring. However, the accuracy of this method has not been well studied. This pilot study aimed to evaluate the accuracy of energy intake (EI) estimated by a web-based food record, by comparison with total energy expenditure (TEE) measured by doubly-labelled water (DLW) in overweight and obese women.

Total energy expenditure (TEE) was assessed in weight stable (±1 kg) women (n = 9), with a mean (SD) age of 34.5 (11.3) years and body mass index of 29.2 (1.4) kg m(-2) over 10 days using the DLW technique. All food and beverages were self-reported for 9-days using a web-based food record and mean daily EI calculated. Food record accuracy was assessed by calculating the absolute (EI - TEE) and percentage (EI/TEE × 100) differences between EI and TEE. Women were identified as under-reporters of EI based on the 95% confidence limits of the expected EI : TEE of 1.

The mean (SD) self-reported EI was 8351 (1225) kJ day(-1) [1996 (293) kcal day(-1) ] and TEE was 10 648 (1774) kJ day(-1) [2545 (424) kcal day(-1) ]. The mean (SD) absolute difference in self-reported EI and TEE was -2301 (1535) kJ day(-1) [-550 (367) kcal day(-1) ], representing a mean reporting accuracy of 79.6% (14.1%), with four participants under-reporting EI.

This pilot study highlights the opportunity for the use of the Internet as a novel medium for recording and assessing dietary intake. Although further research is needed in more diverse population groups, the accuracy of web-based food records for assessing EI appears to be consistent with other published dietary intake methods.