Evaluating the Validity of a Novel Tool to Measure Children's Food Intake and Improve Health
Phase: NA
Conditions: Nutritional Assessment
Sponsor: Pennington Biomedical Research Center

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Protocol Title: Evaluating the validity of a novel tool to measure children's food 
intake and improve health
PI Name: Hanim E. Diktas, Ph.D.
Sub-Investigator’s Name(s): Chloe P. Lozano, Ph.D.; Stephanie Broyles, Ph.D.; 
Amanda E. Staiano, Ph.D.; John W. Apolzan, Ph.D.; Corby K. Martin, Ph.D.; Sanjoy 
Saha Ph.D.
Protocol Version Date: July 01, 2022
Background
Accurate assessment of dietary intake plays a pivotal role in evaluating the nutritional 
adequacy of children’s diet, and; therefore, helps to promote healthy dietary intake and 
management and prevention of nutrition-related childhood diseases such as obesity.1-8 
Childhood obesity is a serious public health challenge in the US,7 and Louisiana ranks 
3rd in the nation for prevalence of obesity in children ages 10-17 years (22.2%).9 
Increased frequency of large portions of high calorie foods is one cause of childhood 
obesity.1,7,8 Low intake of fruits and vegetables is another cause for the higher 
prevalence of obesity.7,9 Therefore, it is important to track energy intake including intake 
of USDA MyPlate food group servings.1,4-6,10 However, accurately measuring energy 
intake (total kcal) and food group servings in real time is challenging due to consumers’ 
inability to accurately estimate the portion size of consumed foods.1-6 Hence, the 
development of valid tools that accurately estimate the dietary intake of school-aged 
children is essential to quantify their dietary patterns and modify intake to improve 
health.1,8 This project aims to adapt an app developed for adults for use in children. 
Drs. Martin and Apolzan from PBRC developed the PortionSize app to facilitate 
personalized dietary intake tracking with just-in-time feedback, and this work builds 
upon over one decade of research.4,5,6,10 To our knowledge, this proposed pilot study 
will be among the first to assess the validity of a smartphone-based app to quantify 
children’s energy intake and provide immediate feedback on intake of USDA MyPlate 
recommended food group servings. 
The PortionSize app uses emerging technology (e.g., augmented reality) which is 
unique and has innovative features to estimate food intake and reduce missing data 
with minimal user burden. Visual comparison procedures and template systems are 
established in the PortionSize app and will help users to correctly estimate portion size 
of food and, thus, energy intake. The PortionSize app estimates food selection (before 
meal) and food waste (after meal) and, thus provides assessment of net food intake. 
PortionSize is the first known method that provides just-in-time feedback on intake of 
energy (kcal), saturated fat (g), added sugar (g), and USDA MyPlate food group 
servings (fruit, vegetable, grain, protein, and dairy). Users will get immediate feedback 
on the diet quality of the plated meal and left-overs from the meal, and cumulatively 
throughout the day. Getting immediate feedback on the plated meal will give users the 
opportunity to modify their plated meal and, thus, their food intake. The PortionSize app 
 
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provides an ‘all-in-one’ platform to both assess dietary patterns and to guide parents 
and their children to follow a healthier eating pattern. 
Many parents are unaware about the importance of their children following a healthy 
dietary pattern and achieving their recommended intake of food group servings.9,11 The 
PortionSize app will allow parents or caregivers to track energy intake and food group 
servings for their children thereby improving the health and nutrition literacy of children 
and parents or caregivers.  
Objectives
The objective of this pilot study is to assess the validity of the PortionSize™ app to 
quantify children’s own dietary intake and children’s intake by parents or caregivers. 
The specific aims are to assess the validity of children’s:  
 
1. (a.) energy intake and (b.) intake of USDA MyPlate recommended food group 
servings (fruit, vegetable, grain, protein, and dairy) as estimated by children using the 
PortionSize app. 
2. (a.) energy intake and (b.) intake of USDA MyPlate food group servings as estimated 
by parents or caregivers with the PortionSize app.  
 
The secondary aim is to quantify children’s and parents’ or caregivers’ user satisfaction 
with the PortionSize app.  
Primary Hypotheses:
1. (a). Estimation of energy intake (kcal) with PortionSize by children will be equivalent 
to known energy estimates (weighted meal) within an equivalence boundary of 25%
1. (b). Estimation of intake of USDA MyPlate recommended food group servings (fruit, 
vegetable, grain, protein, and dairy) with PortionSize by children will be equivalent to 
known food group serving estimates (weighted meal) within an equivalence boundary of 
25% 
 
2. (a). Estimation of energy intake (kcal) with PortionSize by parents will be equivalent 
to known energy estimates (weighted meal) within an equivalence boundary of 25%
2. (b). Estimation of intake of USDA MyPlate recommended food group servings (fruit, 
vegetable, grain, protein, and dairy) with PortionSize by parents will be equivalent to 
known food group serving estimates (weighted meal) within an equivalence boundary of 
25% 
Methods
We will recruit 40 dyads (40 children aged 7-12 years old and 40 parents or 
caregivers) using a convenience sample for this pilot study. Children and their parents 
or caregivers will be trained to use the PortionSize app at Pennington Biomedical 
 
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Research Center (PBRC). For specific aims 1a. and 1b., children will use the 
PortionSize app and estimate food intake from pre-weighed meals at PBRC. For 
specific aims 2.a. and 2.b., their parents or caregivers will use the PortionSize app and 
estimate the food intake of their children (at least one meal and a snack each day) for 
two consecutive days at home. 
Inclusion and Exclusion Criteria
Inclusion and exclusion criteria of participants (children and parents or caregivers) are 
presented in Table 1.
 
Table 1. Inclusion and exclusion criteria (children and parents or caregivers)
Inclusion criteria
Exclusion criteria
•
Children (7-12 years) and their parents 
or caregivers (18-62 years)
•
Any condition or circumstance that 
could impede study completion
•
Parents who have Willingness to use 
the PortionSize app to estimate the 
intake of their child food intake 
(normal/regular diet) from at least a 
snack and a meal of child for two 
consecutive days
•
Child who is a very choosy eater or 
has a very limited food choice
•
Have iPhone (version 6 or above) and 
an operable Apple ID, password, and 
email address, and able to use iPhone
•
Willing to use their own smartphone to 
collect data during the study
Procedures
Screening at PBRC Clinic
Parents or caregivers will need to read and sign an informed consent prior to 
participating in the study. Children will provide an informed assent (verbal assent will be 
accepted for the child aged less than nine years and written with nine years or above 
unless parent or child prefers oral) prior to participating in the study. The eligibility of the 
participants (for both parent or caregiver, and child) to take part in this study will be 
assessed at the PBRC clinic. Afterward, weight and height of children and parents or 
caregivers will be measured by trained staff at PBRC clinic. Parents or caregivers will 
also complete a demographic (parents’ or caregiver’s age, children’s age and date of 
birth, household income, education, etc.), learning disability survey, and lifestyle 
behavior questionnaire of children. Children will complete screen time survey. Prior to 
participants’ visit to clinic, IBL staff will conduct a lifestyle behavior interview via phone 
with parents or caregivers to assess participants’ wiliness and ability to complete the 
study procedures. 
 
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Table 2. Schedule of study procedures
Week 1
Screening 
Visit 
(~Day 1)
Week 1
(~Day 2)
Week 1
(~Day 3)
Informed consent from parents or caregivers and 
assent from children
×
Weight and height of children and parents or 
caregivers
×
Completion of screen-time survey by children and 
children’s learning disability survey by parents or 
caregivers
×
Training on the PortionSize App for children and 
parents or caregivers
×
Assessment of laboratory-based simulated meal 
by children
×
Completion of User Satisfaction Survey by 
children
×
Parents or caregivers will be instructed to use 
app over a 2-day period to measure children’s 
food intake (at least one meal and one snack 
each day) in free-living setting
×
×
Completion of User Satisfaction Survey by 
parents or caregivers (in person or over the 
phone, email, videocall, etc.)
×
Review of images to ensure data quality (in 
person or over the phone or video conference)
×
Screen Time Survey
It has been anticipated that children’s screen exposure time may have influence on the 
using of the PortionSize app; those who have more exposure, will have accurate dietary 
intake estimation using the PortionSize.12 Therefore, we will ask the children three 
questions that were adapted from the National Health and Nutrition Examination 
Survey13 to identify children’s screen time. Questions are: 1) Over the past 30 days, on 
average how many hours per day you sit and watch TV or videos?, 2) Over the past 30 
days, on average how many hours per day you use a computer or tab or play computer 
games or play games using tab or smart phone outside of work or school?, 3) ) Over the 
past 30 days, on average how many hours per day your screen time using apps?.13 
Learning Disability Survey
It has also been suggested that participants who do not have any learning disabilities, 
may perform better using the PortionSize compared to those who have learning 
disability.14 We will include participants who have learning disability when parents or 
caregivers would like their children’s participation in this study. We will administer a 
 
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questionnaire consisting of four questions (binary responses, yes or no) to identify 
children who have any learning disabilities. Questions are: 1) Does your child have a 
history of developmental delay?, 2) Does your child have an individualized educational 
plan at school for learning difficulties?, 3) Does your child have a diagnosed physical 
disability that might affect their ability to use a smart phone app to take pictures of 
food?, and 4) Does your child have a diagnosed developmental or intellectual 
disability?. The questionnaire will be adapted from other studies conducted in PBRC 
and in individualized education programs.15,16 
Directly Weighed Food Intake to Prepare Simulated Test Meals
Trained staff of PBRC will prepare simulated test meals via direct observation. Such 
simulated meals served as the criterion measures of energy content, and food group 
quantity for comparisons with the food intake assessments by children using the 
PortionSize app. Children’ energy requirements will be calculated by using sex-specific 
formulas.17 Energy requirements will be multiplied by 1.3, and the food selection for the 
simulated test meal included 30% of this value, which represents a typical lunch. The 
meals will consist of at least 3 food items and 1 calorie-containing beverage. Menus of 
meals will be selected from a list of commonly consumed foods from a previous study.18 
Plate waste will be determined at the individual food item level. This measure will range 
from 0% and 100% and be right-skewed; as such, the mean plate waste will be around 
5% of the foods provided, which is similar to the actual plate waste from our free-living 
data (around 3%).18 Simulated food provision and plate waste will be covertly weighed, 
and food intake estimation will be calculated by difference.
Using of the PortionSize App
Trained IBL (Ingestive Behavior Lab) staff will facilitate a 30-minute training for children 
and parents or caregivers on how to use the PortionSize app to capture dietary intake 
during their visit at PBRC clinic. Children and parents or caregivers will practice 
assessing food intake with a sample meal as part of the study procedures. Children will 
place a reference card (3.25 x 2 inches) next to the meal and use the PortionSize app 
on their smartphone to capture images of their food selection (“before” image) and plate 
waste (“after” image). Parents or caregivers will do the same to assess their dietary 
intake during the practice session. 
Afterward, for the specific aim 1.a and 1.b, children will follow the same procedures to 
estimate energy and food group servings from a weighed or simulated meal (known 
energy and food group servings) in the clinic on the same day. Children will not eat the 
simulated meal. Children can use their own or parents’ phone to assess food intake. 
Children will be asked whether they know all the served food’s names (from weighed or 
simulated meal) prior to taking a “before meal" photo using PortionSize. If they do not 
know, trained nutritionist will support them to know all the food items’ names from the 
simulated meal so that they can search the food item using the PortionSize app. 
Parents or caregivers will be allowed to attend the training session for children to 
enhance children’s attentiveness. However, parents or caregivers will be requested not 
to support when children assess food intake with simulated meal using the PortionSize 
app.
 
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For the specific aim 2.a and 2.b, parents or caregivers will use the PortionSize app and 
estimate the food intake of their children (at least one meal and a snack each day) for 
two consecutive days at home. Parents or caregivers will be requested to take notes 
when they do not find food items in the PortionSize (a subset of food list from the 
FNDDS) and submit those notes to IBL staff on day 4 in person or over the phone. Such 
information will support us to extend and update the food list in the PortionSize. All the 
data will be automatically transmitted and stored in the Automated Data Management 
Utility (ADMU) and the RFPM image will be analyzed by the nutritionists to measure the 
portion size of the foods and food intake. As RFPM is an affordable dietary intake 
assessment method and the error bounds are known,4,5 and therefore, we are using 
RFPM as a reference method in this study. Parents or caregivers will be informed 
during screening visit that they will receive reminders from IBL if they stop using the 
app.
User Satisfaction Survey
After completing food intake measurement using PortionSize, children will be requested 
to complete a user satisfaction survey at PBRC to evaluate PortionSize on several 
parameters, including ease of use, stratification, and burden. Parents and or caregivers 
will be allowed to be around to assist children to complete the survey, be attentive 
during the training session and help during height and weight assessment.
When the parents or caregivers will visit the PBRC clinic after completing food intake 
measurement using PortionSize for two days, they will complete the same user 
satisfaction survey to evaluate the PortionSize app. If parents or caregivers want, they 
complete this survey over-phone. The user satisfaction survey will be adapted from 
previous studies3,4 conducted at PBRC. 
Outcome Measures and Data Analysis
The primary analyses assessing equivalence between the PortionSize app, and the 
criterion measure will rely on equivalence testing using the Two One-side T-test (TOST) 
method. The criterion measure is the weighed food to compare children’s estimations. 
On the other hand, the criterion measure is the estimated energy (kcal) of the foods 
from the RFPM to compare parents’ or caregivers’ estimations. The equivalence bounds 
are set at +/-25%19 and Bland Altman analysis20 will be used to test for differences in 
error variance over levels of the variable being measured (e.g., energy intake). Error is 
defined as the values from PortionSize minus the respective values from the known 
estimations (weighed meals) to compare children’s estimations. On the other hand, 
error is defined as the values from PortionSize minus the respective values from the 
RFPM to compare parents’ or caregivers’ estimations. Equivalence tests are used to 
quantify validity, though the mean error from PortionSize will be reported from the Bland 
and Altman analyses. Multivariable regression analysis will be performed to determine if 
error differs by the age, sex of the parents and child, screen time, and learning disability 
of children. However, this is a pilot study and therefore the obtained results (variance of 
energy intake) from this study may underpower the regression analysis and Bland 
Altman analysis. User satisfaction will be presented in frequency and percentage.  
Study Timelines
 
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June to December, 2022: IRB submission, development of study materials, recruitment, 
participant training, and food intake estimation by participants using the PortionSize 
app. January to April, 2023: Analyze results and submit peer-reviewed scientific 
manuscripts; and disseminate findings to parents, the healthcare community, and other 
stakeholders. 
Provisions to Monitor the Data to Ensure the Safety of Subjects
Adverse events will be monitored at each intervention visit. The PI and his 
coinvestigators will review all data after a certain interval to ensure the safety of each 
subject.
Withdrawal of Subjects
Subjects may be withdrawn from the study at any time. If a subject voluntarily withdraws 
from the study, no additional data will be collected, and they will be considered dropouts 
in the study. Data already provided will be retained for analysis.
Risks to Subjects
This study involves no greater than minimal risk. The main risk is a breach of 
confidentiality, and the PBRC team will work to minimize this during data collection, 
handling, and analysis.
Potential Benefits to Subjects
Participants may benefit from increased awareness of energy and nutrients in foods 
served. 
Sharing of Results with Subjects
The participants may receive information such as body weight and anthropometrics. 
Those results will be provided to the participant at the end of the study if requested. 
Participants will have access to the study results once published.
Compensation
Each  child will receive $50 and parent or caregiver will receive $75 for the successful 
completion of the study.
Provisions to Protect the Privacy Interests of Subjects
All attempts will be made to maintain a subject’s privacy. Safeguards such as password-
protected computers and networks have been put in place in order to limit access to 
subject data. Subjects will be given ample time to read over the consent and assent, 
ask questions, and agree to participate in the research study. Subjects may decline to 
answer questions with which they are not comfortable. Each procedure will be explained 
to the subject before it is performed. 
Compensation for Research-Related Injury
No compensation will be provided for research-related injury.
Economic Burden to Subjects
All study-related tests and procedures will be at no cost to the subject. However, use of 
the PortionSize app will use data from the participant’s cellular data plan. Hence, it is 
 
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possible that the participant would incur the cost for this data, and this is clearly 
disclosed in the consent form.
Consent and Ascent Process 
After the phone-screening, children and parents or caregivers would like to participate in 
this study, we will email parents or caregivers a copy of the consent and assent form 
ahead of time in case they want to read it, but they will not sign until they get in the 
clinic. A designated and trained staff member will obtain informed consent from parents 
or caregivers and assent from children during the visit. Ample opportunity will be given 
for the subject to review the consent and ascents forms and ask any questions prior to 
signing the form/s. If subjects wish, they can take the form/s home and return at a 
different visit. We are aware that consent is an ongoing process.
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