Abstract:
To avoid the pitfalls of self-reported dietary intake, wearable sensors can be used. Many
food ingestion sensors offer the ability to automatically detect food intake using time
resolutions that range from 23 ms to 8 min. There is no defined standard time resolution
to accurately measure ingestive behavior or a meal microstructure. This paper aims to
estimate the time resolution needed to accurately represent the microstructure of meals
such as duration of eating episode, the duration of actual ingestion, and number of
eating events. Twelve participants wore the automatic ingestion monitor (AIM) and kept
a standard diet diary to report their food intake in free-living conditions for 24 h. As a
reference, participants were also asked to mark food intake with a push button sampled
every 0.1 s. The duration of eating episodes, duration of ingestion, and number of eating
events were computed from the food diary, AIM, and the push button resampled at
different time resolutions (0.1–30s). ANOVA and multiple comparison tests showed that
the duration of eating episodes estimated from the diary differed significantly from that
estimated by the AIM and the push button (p-value <0.001). There were no significant
differences in the number of eating events for push button resolutions of 0.1, 1, and
5 s, but there were significant differences in resolutions of 10–30s (p-value <0.05). The
results suggest that the desired time resolution of sensor-based food intake detection
should be ≤5 s to accurately detect meal microstructure. Furthermore, the AIM provides
more accurate measurement of the eating episode duration than the diet diary