The PortionSize Smartphone App Pilot (PS Pilot)


The objective is to examine the preliminary validity, reliability and perceived participant satisfaction of the PortionSize app.

Full Title of Study: “Pilot Validation of an App to Estimate and Manage Portion Size: The PortionSize Smartphone App”

Study Type

  • Study Type: Observational
  • Study Design
    • Time Perspective: Prospective
  • Study Primary Completion Date: December 31, 2020

Detailed Description

Overweight and obesity are a burgeoning public health concern, yet only a small minority of smartphone apps that claim to facilitate healthy eating and weight loss incorporate evidence-based principles. Such innovations are important as humans fundamentally cannot accurately estimate portion size. Indeed, portion size estimation errors account for ~50% of the error in self-reported food intake, and data from our laboratory has demonstrated that extensive training results in only modest improvements in portion size estimation accuracy and that portion size estimates remain inaccurate. Our long-term goal is to create simple and accessible interventions that assist individuals with weight control. In particular, we aim to provide easy-to-use phone apps that allow participants to monitor the portion sizes of the foods they consume. These apps guide participants on appropriate portion sizes and provide recommendations of food groups that should be consumed. To that end, we have developed the PortionSize app. We propose to improve the accuracy of portion size measurement, as it is poorly determined by self-report measures. This will occur via the development of the PortionSize smartphone app and this pilot study will test the usability as well as preliminary validity and reliability of the app functionality.

Clinical Trial Outcome Measures

Primary Measures

  • Validity of portion size at estimating energy intake
    • Time Frame: August – December 2020
    • Compared measurements from PortionSize to weighed values in the lab.
  • Reliability of portion size at estimating energy intake
    • Time Frame: August – December 2020
    • Quantify the reliability of app measurements over time in free-living conditions.

Secondary Measures

  • User satisfaction
    • Time Frame: August – December 2020
    • Participant ratings of the PortionSize App

Participating in This Clinical Trial

Inclusion Criteria

  • BMI 18.5-45 kg/m2 based upon self-reported height and weight
  • Have an iPhone and an operable Apple ID, password, and email address and is willing to use these to collect data during the study, acknowledging that data usage, and associated charges, are a result of study participation

Exclusion Criteria

  • For females, pregnancy or breast feeding
  • Currently diagnosed with an eating disorder
  • Disease that severely affects metabolism, including diabetes, hypercholesterolemia, or dyslipidemia
  • Has gained or lost more than 10 lbs in the last 3 months
  • PBRC faculty/staff member
  • Has suffered serious mental illness that has resulted in serious functional impairment and has substantially interfered with one's life activities within the last 5 years
  • Any other medical, psychiatric, or behavioral factors in the judgment of the Principle Investigator that may interfere with study participation or the ability to follow the protocol

Gender Eligibility: All

Minimum Age: 18 Years

Maximum Age: 65 Years

Investigator Details

  • Lead Sponsor
    • Pennington Biomedical Research Center
  • Provider of Information About this Clinical Study
    • Principal Investigator: Corby K. Martin, PBRC Professor, Director – Ingestive Behavior Laboratory – Pennington Biomedical Research Center
  • Overall Official(s)
    • John Apolzan, PhD, Principal Investigator, Pennington Biomedical Research Center
    • James Dorling, PhD, Principal Investigator, Pennington Biomedical Research Center
    • Corby Martin, PhD, Principal Investigator, Pennington Biomedical Research Center
  • Overall Contact(s)
    • Jessica St Romain, 225-763-2921,

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