Leveraging AI to Transform Dietary Choices for Cardiovascular Health in Young Adults Experiencing Food Insecurity
Phase: NA
Conditions: Healthy
Sponsor: University of California, Davis

Study Protocol and Statistical Analysis Plan 
 
Leveraging AI to transform dietary choices for cardiovascular health in young 
adults experiencing food insecurity  
NCT Number: not yet assigned  
Date approved: 06/04/2025 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 

1) 
Protocol Title 
a) Title: Using an AI mobile application to promote healthy eating 
 
b) Protocol Version Date: version 1; 04/29/2025 
 
2) 
Objectives 
a) Describe the purpose, specific aims, or objectives: 
a. Aim 1: To assess the accuracy of PlantVillage Food against the gold standard 
of observed weighed food records (WFR). 
b. Aim 2: To determine the feasibility (adherence, acceptability, and usability) 
of the behavioral intervention of PlantVillage Food and its effects on food 
choices and diet quality. 
c. Aim 3. To assess whether the accuracy or feasibility of PlantVillage Food 
varies by food security status. 
 
b) State the hypotheses to be tested: 
a. Hypothesis 1. PlantVillage Food will accurately estimate nutrient intake 
compared with WFR in U.S. college-aged students. 
b. Hypothesis 2a. The PlantVillage Food app will be considered feasible by 
participants. Exploratory Hypothesis 2b. Differences in food choices and diet 
quality will be observed by intervention vs. control groups. 
c. Hypothesis 3. There will be no differences in accuracy, adherence, 
acceptability, and usability measures between food secure vs food-insecure 
households. 
 
c) Describe how this research will add to existing knowledge or how the outcomes of this 
project will be used: 
PlantVillage Food will be one of the first valid AI-assisted dietary tools in the U.S. that 
could transform the implementation of future dietary interventions. 
 
3) 
Enrollment Numbers 
a) Total number of subjects to be enrolled in this study: 180; 66 for the validation study, 
114 for the pilot RCT. 
 
b) If this is reliance, list the number of subjects to be enrolled at each site (UC Davis: #, 
Relying Site 1: #, Relying site 2: #): N/A 
 
c) Provide a rationale (e.g., statistical justification, power analysis, etc. for the number of 
subjects to be enrolled: 
Sixty-six participants aged 18-24 will be recruited from the UC Davis campus student 
population and will provide 90% power to conclude equivalence between PlantVillage 
Food and the WFR, with a 15% equivalence margin while allowing for 20% attrition. 
 
4) 
Inclusion and Exclusion Criteria 

a) Inclusion Criteria: Receiving a residential meal plan (or eat most meals from the 
dining commons, i.e., 5/7 day meal plan) in the dining commons, willing to use their 
personal smartphone with the PlantVillage Food application, and willing to record 
their food consumption using the app, and having their foods weighed. 
 
b) Exclusion Criteria: Not willing to be followed up during the WFR, under 18 or over 
24 years old, not receiving the 5 or 7 day meal plan, and screened for disordered 
eating behavior. 
 
c) Age Range: 18-24 years 
 
d) If applicable, describe the screening procedures to determine eligibility: The SCOFF 
questionnaire (https://pmc.ncbi.nlm.nih.gov/articles/PMC1070794/), consisting of 
five questions designed to screen for eating disorders, will be utilized to identify 
students who may have an eating disorder. A threshold of two or more affirmative 
responses to the five questions will serve as an indicator of an eating disorder. 
Additionally, the screening questionnaire includes a question about food insecurity 
experiences in the past 12 months. 
 
 
5) 
Procedures Involved 
Aim 1: Each participant will visit the dining commons on 3 days, including 1 day for 
recruitment, consent, and training, followed by 2 nonconsecutive days for WFR. Research 
assistants will obtain consent, help the participant download the PlantVillage Food app, and 
train participants on PlantVillage Food application use on the day of recruitment. A 
PlantVillage Food video tutorial will also be available on the app for reference, emphasizing 
a dynamic training approach. Following the recruitment visit, participants will return to 
collect the WFR, recording all instances of food and beverage consumption at the dining 
commons concurrently as participants recorded foods and beverage consumed using 
PlantVillage Food. Research assistants will record the weights of foods and beverages 
consumed in the dining commons. 
Participant access to the app will be removed upon completion of the study. 
 
Aim 2: Participants will be randomized at enrollment into either intervention or control 
groups, where participants in the control group will receive a version of PlantVillage Food 
with functionality limited to dietary assessment (here referred to as limited PlantVillage 
Food), and the intervention group will receive a gamified PlantVillage Food interface. The 
research team will separately train participants in both groups on how to record food 
consumption on PlantVillage Food. A 2-day troubleshooting period will allow participants 
to practice using PlantVillage Food to record food consumption and identify problems related 
to application use. On day 4, participants in both groups will be free to use PlantVillage Food 
for the following 6 weeks. 
Participant access to the app will be removed upon completion of the study. 
 
Aim 3: To recruit a representative sample of students from food-insecure backgrounds, we 
will aim to recruit first-generation, transfer, Pell Grant-eligible, and low-income students. 

We will recruit through campus events and offices on campus that interact with these student 
groups and have previously shown high rates of food insecurity with unlimited dining 
commons meal plans ensuring the reach of diverse under-represented students. Participants 
will then be randomly selected for participation. In addition to using the PlantVillage Food 
app and collecting WFR, we will also collect food insecurity status at enrollment using a 
demographic questionnaire. 
 
Surveys/Questionnaires 
• Background information on participants’ socioeconomic status will be collected 
using a structured questionnaire that will include questions about age, race and 
ethnicity, biological sex, food insecurity, and federal nutrition assistance 
participation (i.e., SNAP). 
• Food Security: The validated USDA 10-item Food Security Survey Module will 
capture food security over the prior 12 months and be administered at the recruitment 
visit. 
• Acceptability and usability will be assessed using a structured questionnaire based on 
a Likert scale from 1 (strongly agree) to 5 (strongly disagree) administered at the end 
of the study period. 
Statistical Analysis Procedures 
Aim 1: Descriptive statistics will be used to characterize energy and nutrient intakes by 
person-day. To ensure comparability across the 2 methods, consumption periods will be 
matched across the 2 methods, excluding foods that were reportedly consumed outside the 
WFR period. Bland–Altman plots will be used to visualize differences in intakes for the 
different methods compared with the average intake by method. Equivalence testing with a 
15% equivalence margin will be undertaken using the two 1-sided paired t-test method, 
examining mean differences of log-transformed nutrient intakes using mixed-effect models 
including a random effect at the person level to account for the repeated measures. The 
differences in log-transformed intakes will be equivalent to ratios where the numerator is the 
intake as estimated by PlantVillage Food and the denominator is the intake from the WFR. 
The extent of agreement between methods will be examined using the concordance 
correlation coefficient (CCC) with bootstrapped standard errors. Sources of error will be also 
examined by individual foods including 1) instances of omissions (foods consumed but not 
reported) and intrusions (foods reported that were not consumed) for PlantVillage Food and 
WFRs and 2) portion estimation errors, assessed by comparing the reported food amounts by 
PlantVillage Food to the observed amounts by WFR for the top 20 most commonly 
consumed foods. 
 
Aim 2: Descriptive statistics will summarize socioeconomic characteristics for intervention 
and control groups. The primary objective is to estimate feasibility measures for the full 
sample, and as a secondary objective will be assessed separately by the intervention arm to 
test whether gamification reduces adherence or likability. Data will be longitudinal as 
outcome data will be generated throughout the 6 weeks. All models will include a random 
effect of participants to account for the repeated measures. Linear regression will be used for 
continuous outcomes and modified Poisson regression for dichotomous. Modeling will 
include an evaluation of group differences across the full study period as well as changes 

over time (group x time interaction). The interaction between the time variable and the 
dummy for the PlantVillage Food version will be included because users will take time to 
adapt to new technologies, so the effect of PlantVillage Food could change with time. 
 
Aim 3: Moderation by food security status will be assessed by including an interaction term 
between the assessment method and binary food security in the Aim 1 and 2 models. If p-
for-interaction<0.10, then parameter estimates will be re-assessed within each of the two 
food security strata. 
 
6) 
Study Timelines 
a) Duration of an individual subject’s participation in the study: Validation study: 3 days in 
the fall quarter 2025, i.e., ~40-50 minutes at enrollment visit, 5-7 hours total for 2 WFR 
days; Feasibility study (pilot RCT): 6 weeks in the winter-spring quarters 2026, 
approximately 10-20 hours’ time commitment. 
 
b) Estimated timeline to enroll all study subjects: 1 quarter (10 weeks) 
 
c) Estimated timeline for the investigators to complete this study (complete primary 
analyses): The study is expected to span a period of 3 years, with data collection 
estimated to take about 1 year, followed by data cleaning and analysis, and dissemination 
of results. 
 
 
7) 
Study Endpoints 
a) Describe the primary and secondary study endpoints: Validation study: Completion of 
2 days of weighed food records; Outcome: accuracy of the mobile application.  
Six-week intervention period- Primary outcome: app feasibility (usability and 
acceptability) Secondary outcome: Diet quality. Exit survey: Completion of an endline 
survey assessing application acceptability. 
 
b) Describe any primary or secondary safety endpoints: N/A 
 
 
8) 
Recordings 
This research involves: 
☐ Audio recordings 
☒ Photographs [of food] 
☐ Video recordings with audio 
☐ Video recordings without audio 
☐ None of the above 
 
9) 
Data and/or Specimen Management and Confidentiality 
Before completing this section, see Privacy and Confidentiality and HIPAA Guidance. 

 
a) List any identifiers that will be collected during this study (e.g., name, medical record 
number, date of birth, video recordings, etc.): Name, email address, and phone number. 
 
b) If any identifiers will be stored, how long will they be kept? 1-2 years after the study's 
completion. 
 
c) For data that is coded with a linking key, at what point will the linking key be 
destroyed? 1-2 years after the study's completion. 
 
d) For any recordings, at what point will the recordings be destroyed? N/A 
 
e) If this research is both federally funded and you are using identifiable data/specimens, 
please explain why this research cannot be completed using de-identified 
data/specimens: N/A 
NOTES ABOUT USE OF RECORDS 
UC Davis Medical Records: UC Davis Health Electronic Health Record (EMR/EPIC) also 
contains the clinical data for Marshall Medical Center (MMC). MMC patient data cannot 
be accessed for research purposes. Researchers must take the necessary steps to ensure that 
MMC data is not accessed, used, or disclosed for UC Davis Health research purposes. 
If protected health information or personal information from the medical records will be 
stored on an encrypted device, investigators must follow applicable university policies (UC 
Davis Hospital Policy 1313, UCDHS P&P 2300-2499, and UC Business and Finance 
Bulletin on Information Security (IS-3)). Please contact the Biomedical Informatics 
Department for assistance with data security. 
 
If identifiable protected health information is extracted from the UCDH EMR, it may not 
be re-disclosed/released outside the study team. 
 
UC Davis Student Education Records: If this study involves use of UC Davis students’ 
educational records (including records in the PI’s own possession such as course 
exams/assignments), you must consult with the Registrar’s office to see if all requirements 
of the Family Educational Rights and Privacy Act (FERPA) are satisfied. 
 
10) Provisions to Monitor the Data to Ensure the Safety of Subjects 
N/A 
11) Withdrawal of Subjects 
The sample size was calculated to account for 20% attrition. 
 
12) Risks to Subjects 
☒ This research may pose the risk of loss of confidentiality. The risk will be minimized 
through the data protection plan.  
13) Potential Benefits to Subjects 
☒ Research subjects are not likely to receive any benefit from the proposed research, but 
others may benefit from the knowledge obtained. 

 
14) Provisions to Protect the Privacy Interests of Subjects 
Survey questionnaires will be electronic and self-administered to ensure data privacy. At 
enrollment, participants will complete sociodemographic and food security surveys, and at 
the endline, an acceptability questionnaire using a Qualtrics survey on study-provided 
tablets. Research assistants will be available to answer any questions and assign participant 
IDs but will not have access to participants' responses. 
 
15) Sharing of Results with Subjects 
☐ Results will not be shared with subjects 
☒ Results will be shared with subjects - Describe: A newsletter summarizing the general 
study findings will be prepared and made available to the UC Davis community. 
 
a) If results will be shared, describe the results (study results or individual subject 
results such as results of investigational diagnostic tests, genetic tests, or incidental 
findings) to be shared with subjects or others (e.g., the subject’s primary care 
physicians). 
Note: There are restrictions on the information that can be provided to individuals 
when the tests performed on their specimens are considered investigational or the 
tests are not being performed at a CLIA-certified laboratory. 
 
 
16) Data Banking 
a) Will the data ever be used by you or other researchers to answer a different research 
aim that is not included in this study? 
☒ Yes - Complete the remainder of Section 16. 
☐ No - Do not complete Section 16. Go to section 17. 
 
b) What will be banked for future use? 
☒ De-identified data. Banked data cannot be linked to an individual. 
☐ Identifiable data/specimens – Banked data/specimens will include identifying 
information. 
☐ Coded data/specimens – Banked data/specimens will be stripped of identifiers and 
assigned a code. A key will be maintained that links the identifiers to the 
data/specimens. 
☐ Contact information will be banked for future research opportunities. 
 
c) Where will the data be banked?  UC Davis Box folder with secure access. 
 
d) How long will the data be banked? 5 years after the conclusion of the study. 
 
e) Who will have access to the banked data/specimens? The PI, project manager, 
statistician, and graduate students involved in the study. 

 
f) Describe the procedures to release data. Include the process to request a release, the 
approvals required for release, who can obtain data, and the data to be provided.  
Note: Identifiable protected health information extracted from the UCDH EMR under 
an IRB-issued waiver of HIPAA Authorization may not be re-disclosed/released 
outside the study team. 
Only the study’s principal investigators, co-investigators, and research staff will have access to 
the data, which will be de-identified. Data will be made available upon reasonable request. 
 
17) Multi-Site Research 
N/A 
 
18) Community-Based Participatory Research 
N/A 
 
19) Compensation for Research-Related Injury 
N/A 
 
20) Economic Burden to Subjects 
Eligible participants will have a meal plan and access to the dining commons and as such, 
will not incur any additional costs. 
 
 
21) Review Requirements 
Some research projects require specific IRB determinations. 
 
a) Are there any contractual obligations or other considerations that require IRB review of 
this research, or review at intervals other than those required by the Common Rule or 
FDA? 
☐ Yes 
☒ No 
 
b) If yes, please describe: