Mathematical models have been formulated that allow energy intake (EI) to be estimated by solving the equation energy storage (ES) = EI – energy expenditure (EE).  Accurately assessing EI is difficult because of self-reporting bias or the expense of conducting analyses using the gold standards, which include doubly labeled water for EE and DXA for ES.  It is possible to use consumer devices to estimate ES and EE, and thus to calculate EI, however, the validity, repeatability and measurement error of the data acquired with those devices is not known.  Shook and colleagues explored this issue and report their results in the February 2022 issue of The Journal of Nutrition.

Healthy adults (14 women and 10 men) participated in two 14-day assessment periods in which EE and ES were determined using the gold standard approaches and with commercially available devices.  An estimate of EI was determined by dietician-administered recalls.  Accuracy and validity of the device derived results were determined, as was measurement error using a within-subject repeated-measurers design.

Moderate to strong agreement was obtained between the gold standard and the device for EE, but only weak agreement was obtained for ES.  The strongest correlations for EI were obtained for dietary recalls and the value calculated using data derived with the gold standard techniques.  These observations led the authors to conclude that EE was most robustly estimated by commercial devices but that ES was poorly estimated by current consumer-available devices.

In an editorial, Gebel and Ding state that without an accurate measure of both EE and ES it will not be possible to develop a valid estimate of EI using commercial-grade devices.  They describe the many reasons why it is difficult to use commercially-derived devices for research.  However, they suggest that these devices may become a viable option once the validity of body composition measurements is increased.


Robin P Shook, Hung-Wen Yeh, Gregory J Welk, Ann M Davis, Daniel Ries, Commercial Devices Provide Estimates of Energy Balance with Varying Degrees of Validity in Free-Living Adults, The Journal of Nutrition, Volume 152, Issue 2, February 2022, Pages 630–638,

Klaus Gebel, Ding Ding, Using Commercially Available Measurement Devices for the Intake-Balance Method to Estimate Energy Intake: Work in Progress, The Journal of Nutrition, Volume 152, Issue 2, February 2022, Pages 373–374,

Images via