CalNag: Effortless Multiuser Calorie Tracking.

Self-tracking of food intake has been studied at length, but many challenges still remain. Current systems often require significant effort from users, and work that has tried to reduce it resulted in low accuracy or delays. Effort is a major barrier to long term use of self-tracking systems. We propose CalNag, a system that integrates a weighing scale, a barcode reader, and a cloud based service. Together, they allow users to track accurate calorie consumption when preparing food at home, requiring minimal effort for each interaction with the system. Through hand-geometry bio-identification, CalNag seamlessly works for multiple users. We have developed a working prototype and conducted a pilot user study. Our results suggest that CalNag's architecture is a promising solution to effectively promote long term self-tracking of diet.