Evaluating the Validity of the PortionSize Smartphone Application for Estimating Dietary Intake in Free-Living Conditions: A Pilot Study

Authors

Hanim E. Diktas, University of Louisiana System
Chloe P. Lozano, University of Louisiana System
Sanjoy Saha, University of Louisiana System
Stephanie T. Broyles, University of Louisiana System
Corby K. Martin, University of Louisiana System
John W. Apolzan, University of Louisiana System

Document Type

Article

Publication Date

9-1-2024

Abstract

Objective: Evaluate the validity of the PortionSize application. Methods: In this pilot study, 14 adults used PortionSize to record their free-living food intake over 3 consecutive days. Digital photography was the criterion measure, and the main outcomes were estimated intake of food (grams), energy (kilocalories), and food groups. Equivalence tests with ±25% equivalence bounds and Bland-Altman analysis were performed. Results: Estimated gram intake from PortionSize was equivalent (P < 0.001) to digital photography estimates. PortionSize and digital photography estimated energy intake, however, were not equivalent (P = 0.08), with larger estimates from PortionSize. In addition, PortionSize and digital photography were equivalent for vegetable intake (P = 0.01), but PortionSize had larger estimates of fruits, grains, dairy, and protein intake (P >0.07; error range 11% to 23%). Conclusions and Implications: Compared with digital photography, PortionSize accurately estimated food intake and had reasonable error rates for other nutrients; however, it overestimated energy intake, indicating further application improvements are needed for free-living conditions.

Recommended Citation

Diktas, H., Lozano, C., Saha, S., Broyles, S., Martin, C., & Apolzan, J. (2024). Evaluating the Validity of the PortionSize Smartphone Application for Estimating Dietary Intake in Free-Living Conditions: A Pilot Study. Retrieved from https://repository.lsu.edu/clinical_research_pubs/93