Dietary HabitsNCT05166226
PortionSize Study 2 Free-Living Evaluation
An observational study of Dietary Habits, run by Pennington Biomedical Research Center at 1 site in United States.
Trial summary
The objective is to test the accuracy of the PortionSize™ app and the MyFitnessPal© app at measuring energy and nutrient intake in free-living conditions. Participants will use PortionSize™ and MyFitnessPal apps in separate periods to test the accuracy of the respective apps. Read more about this study
- Who is it for?
- Ages 18 to 62 yearsHealthy volunteers can take part
- Conditions the study is for
- Dietary Habits
- How many people
- 45 participants
- Where
- 1 siteUnited States
- Study dates
- 10 Jan 2022to 31 Mar 2026
- Phase
- Observational
- Are there results?
- Yes, posted in the registrySummary in the doctors' view
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 62 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy participants ages 18 to 62 in the Baton Rouge, LA area
Who may be able to join
- Male or female, age 18-62 years
- Body mass index (BMI) 18.5-50 kg/m2
- Subjects who are capable of giving informed consent and complying with all study procedures/requirements.
- Ownership of an iPhone model 6s or later, which the participant is willing to use for the study
- Access to Apple ID, password, and email address and willing to use them during the study
- Willing to use data and any accompanying charges as part of study participation
- Willing to complete all study procedures and adhere to study visit timelines
- Willing to be re-contacted for future research and/or follow-up
Who cannot join
- Active cancer diagnosis (excluding some melanomas)
- Have been 6-month weight unstable (gain/loss >10 lbs in last 6 months)
- Undergoing weight loss treatment
- PBRC employee, as previous reviewers argued that they are not representative of the community
- Women who are currently pregnant or breastfeeding (self-reported)
- Diagnosed with an uncontrolled thyroid disorder (controlled = 3 months of medication)
Show all 11Show fewer
- Have had or plan to have weight loss surgery (gastric band removal may be allowed at PI discretion)
- Allergic to or unwilling to eat study foods provided (exceptions made at the discretion of the PI)
- Consume >28 alcoholic beverages per week
- Anyone severely immunocompromised
- Any condition or circumstance that in the judgement of the PI could interfere with study participation
Trial locations and contacts
1 site in 1 country.
United States1 site
Pennington Biomedical Research Center
Baton Rouge, Louisiana, 70808
About this study
Official title: The Reliability and Validity of the PortionSize™ and MyFitnessPal Apps (Study 2: Semi-controlled, Free-living Evaluation)
The objective is to test the accuracy of the PortionSize™ app and the MyFitnessPal© app at measuring energy and nutrient intake in free-living conditions. Participants will use PortionSize™ and MyFitnessPal apps in separate periods to test the accuracy of the respective apps.
Read the detailed description
Accurately quantifying food intake is vital to promoting health and reducing chronic disease risk. Food intake encompasses energy intake, nutrient intake (macronutrients, micronutrients, vitamins, minerals), and intake of various food groups (e.g., fruits, vegetables), and thus reflects the nutritional status of individuals. Nutrition affects disease risk, including risk of developing obesity, diabetes, and cancer, all of which negatively affect the United States (U.S). Nonetheless, accurate assessment of food and nutrient intake has remained challenging, despite an improvement in methods. Self report methods, namely food records, are a mainstay of nutritional epidemiology research, with food recall being another popular method. These methods rely on the participant to accurately estimate portion size and, for food recall, remember what was consumed. The accuracy of these methods have been questioned and the problems with human recall have been comprehensively outlined. As a result, there remains a significant need for methods that are sufficiently accurate to provide researchers with good outcome data and to guide health promotion efforts.
The PortionSize™ app was designed by our laboratory to overcome the limitations outlined above, and to guide users to follow specific diets. PortionSize™ relies on users capturing images of their food selection and waste. Food intake data are immediately provided since the user relies on built in tools, including templates, to estimate portion size. However, despite promising early indications, the PortionSize™ app has yet to be fully validated. Determining the accuracy and reliability of PortionSize™ is vital before the app can be used by people to obtain immediate feedback about their food intake. We accordingly aim to test the reliability and validity of PortionSize™ in a semi-controlled free-living environment using food provision, where participants consume pre-weighed food from a cooler and return the plate waste in the cooler. We will also test the reliability and validity of the MyFitnessPal app in the same semi-controlled free-living environment. The accuracy of the apps will also be compared to each other.
- Conditions
- Dietary Habits
- Medical subject headings
- Feeding Behavior
What is being measured
The primary outcome is the main question the study is designed to answer.
Energy (Kilocalorie or kcal) Intake
The primary analyses assessing equivalence between PortionSize™ and the criterion measure (and MyFitnessPal and the criterion measures) will rely on equivalence testing using the Two One-side T-test (TOST) method. The null hypothesis of an equivalence tests is that the means are nonequivalent, i.e., the confidence interval of the mean of the test condition exceeds the pre-specified error bound. The alternative hypothesis is that the means are equivalent, and the mean difference between the experimental method and gold standard is hypothesized to be zero. Differences in error from PortionSize™ compared to error from MyFitnessPal will be assessed using dependent samples t-tests, with error calculated as the difference between each experimental method and the criterion variable (e.g., energy intake values from PortionSize™ minus energy intake values from weighed foods). These procedures will also produce results indicating if the error from each method differs from zero.
Measured: Mean daily energy intake averaged across 3 day free-living period of each PortionSize app and MyFitnessPal app intervention.
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted21 Dec 2021
- Study start10 Jan 2022
- Primary completion11 Nov 2022
- Study completion31 Mar 2026
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Posted resultsParticipant flow, outcome measures and adverse events reported by the sponsor.
- Publications (1)Papers the sponsor has linked to this study.
- Other trials for Dietary HabitsStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Observational
- Observational model
- Case only
- Time perspective
- Prospective
- Enrolment
- 45 participants (actual)
Sponsor and investigators
- Lead sponsor
- Pennington Biomedical Research Center
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Corby K. Martin, Pennington Biomedical Research Center
- Investigators
- Corby K Martin, PhD, Principal investigator, Pennington Biomedical Research CenterJohn W Apolzan, PhD, Principal investigator, Pennington Biomedical Research Center
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT05166226
- Sponsor's protocol ID
- PBRC 2019-061
- Status last verified
- Apr 2026
- First submitted
- 8 Dec 2021
- Last updated
- 13 May 2026
- Results posted
- Yes, on ClinicalTrials.gov
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Publications
Diktas HE, Lozano CP, Saha S, Broyles ST, Martin CK, Apolzan JW. Validity of the PortionSize and MyFitnessPal Smartphone Applications for Estimating Dietary Intake: A Randomized Crossover Clinical Trial. J Nutr. 2025 Dec;155(12):4296-4306. doi: 10.1016/j.tjnut.2025.09.027. Epub 2025 Sep 27.
PubMed 41022156
Study at a glance
From the registry record, last updated by the sponsor on 13 May 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- The Reliability and Validity of the PortionSize™ and MyFitnessPal Apps (Study 2: Semi-controlled, Free-living Evaluation)
- ClinicalTrials.gov ID
- NCT05166226
- Acronym / sponsor ID
- PBRC 2019-061
- Conditions
- Dietary Habits
- Study type
- Observational
- Recruitment status
- Completed
- Enrolment
- 45 participants (actual)
- Lead sponsor
- Pennington Biomedical Research CenterUniversity, hospital or other
- Study start
- 10 Jan 2022 (actual)
- Primary completion
- 11 Nov 2022 (actual)
- Study completion
- 31 Mar 2026 (actual)
- First posted
- 21 Dec 2021 (actual)
- Results
- Posted 15 Dec 2025
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
The objective is to test the accuracy of the PortionSize™ app and the MyFitnessPal© app at measuring energy and nutrient intake in free-living conditions. Participants will use PortionSize™ and MyFitnessPal apps in separate periods to test the accuracy of the respective apps.
Detailed description
Accurately quantifying food intake is vital to promoting health and reducing chronic disease risk. Food intake encompasses energy intake, nutrient intake (macronutrients, micronutrients, vitamins, minerals), and intake of various food groups (e.g., fruits, vegetables), and thus reflects the nutritional status of individuals. Nutrition affects disease risk, including risk of developing obesity, diabetes, and cancer, all of which negatively affect the United States (U.S). Nonetheless, accurate assessment of food and nutrient intake has remained challenging, despite an improvement in methods. Self report methods, namely food records, are a mainstay of nutritional epidemiology research, with food recall being another popular method. These methods rely on the participant to accurately estimate portion size and, for food recall, remember what was consumed. The accuracy of these methods have been questioned and the problems with human recall have been comprehensively outlined. As a result, there remains a significant need for methods that are sufficiently accurate to provide researchers with good outcome data and to guide health promotion efforts.
The PortionSize™ app was designed by our laboratory to overcome the limitations outlined above, and to guide users to follow specific diets. PortionSize™ relies on users capturing images of their food selection and waste. Food intake data are immediately provided since the user relies on built in tools, including templates, to estimate portion size. However, despite promising early indications, the PortionSize™ app has yet to be fully validated. Determining the accuracy and reliability of PortionSize™ is vital before the app can be used by people to obtain immediate feedback about their food intake. We accordingly aim to test the reliability and validity of PortionSize™ in a semi-controlled free-living environment using food provision, where participants consume pre-weighed food from a cooler and return the plate waste in the cooler. We will also test the reliability and validity of the MyFitnessPal app in the same semi-controlled free-living environment. The accuracy of the apps will also be compared to each other.
Study design
- Observational model
- Case only
- Time perspective
- Prospective
Who may qualify
- Ages
- 18 to 62 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy participants ages 18 to 62 in the Baton Rouge, LA area
Key inclusion criteria (8 listed)
- Male or female, age 18-62 years
- Body mass index (BMI) 18.5-50 kg/m2
- Subjects who are capable of giving informed consent and complying with all study procedures/requirements.
- Ownership of an iPhone model 6s or later, which the participant is willing to use for the study
- Access to Apple ID, password, and email address and willing to use them during the study
Key exclusion criteria (11 listed)
- Active cancer diagnosis (excluding some melanomas)
- Have been 6-month weight unstable (gain/loss >10 lbs in last 6 months)
- Undergoing weight loss treatment
- PBRC employee, as previous reviewers argued that they are not representative of the community
- Women who are currently pregnant or breastfeeding (self-reported)
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
Energy (Kilocalorie or kcal) Intake
Time frame: Mean daily energy intake averaged across 3 day free-living period of each PortionSize app and MyFitnessPal app intervention.
The primary analyses assessing equivalence between PortionSize™ and the criterion measure (and MyFitnessPal and the criterion measures) will rely on equivalence testing using the Two One-side T-test (TOST) method. The null hypothesis of an equivalence tests is that the means are nonequivalent, i.e., the confidence interval of the mean of the test condition exceeds the pre-specified error bound. The alternative hypothesis is that the means are equivalent, and the mean difference between the experimental method and gold standard is hypothesized to be zero. Differences in error from PortionSize™ compared to error from MyFitnessPal will be assessed using dependent samples t-tests, with error calculated as the difference between each experimental method and the criterion variable (e.g., energy intake values from PortionSize™ minus energy intake values from weighed foods). These procedures will also produce results indicating if the error from each method differs from zero.
Results and safety
Loading the posted results from ClinicalTrials.gov…
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 13 May 2026.
- Posted resultsParticipant flow, baseline, all outcome measures and adverse events.
- Derived from this study: PubMed 41022156Diktas HE, Lozano CP, Saha S, Broyles ST, Martin CK, Apolzan JW. Validity of the PortionSize and MyFitnessPal Smartphone Applications for Estimating Dietary Intake: A Randomized Crossover Clinical Trial. J Nutr. 2025 Dec;155(12):4296-4306. doi: 10.1016/j.tjnut.2025.09.027. Epub 2025 Sep 27.
- Individual participant dataSharing planned: Undecided
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Corby K Martin, PhD principal investigator
Pennington Biomedical Research Center
John W Apolzan, PhD principal investigator
Pennington Biomedical Research Center
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Dietary Habits, run by Pennington Biomedical Research Center at 1 site in United States.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 8 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 13 May 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
Yes. Results are posted in the registry (first posted 15 Dec 2025). A summary is in the For doctors view, and the full results are on ClinicalTrials.gov.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Energy (Kilocalorie or kcal) Intake (time frame: Mean daily energy intake averaged across 3 day free-living period of each PortionSize app and MyFitnessPal app intervention.). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT05166226, which also lists 1 linked publication.
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 13 May 2026.