A Systematic Review of Sensor-Based Methodologies for Food Portion Size Estimation

Food portion size estimation (FPSE) is critical in dietary assessment and energy intake estimation. Traditional methods such as visual estimation are now replaced by faster, more accurate sensor-based methods. This article presents a comprehensive review of the use of sensor methodologies for portion size estimation. The review was conducted using the PRISMA guidelines and full texts of 67 scientific articles were reviewed. The contributions of this article are three-fold: i) A taxonomy for sensor-based (SB) FPSE methods was identified, classifying the sensors (as wearable, portable and stationary) and the methodology (as direct and indirect). ii) A novel comprehensive review of the state-of-the-art SB-FPSE methods was conducted and 5 sensor modalities (Acoustic, Strain, Imaging, Weighing, and Motion sensors) were identified. iii) The accuracy of portion size estimation and the applicability to free-living conditions of these SB-FPSE methods were assessed. This article concludes with a discussion of challenges and future trends of SB-FPSE.