Healthy AdultsI-CANNCT04933656
Use of Stable Carbon And Nitrogen Isotopes to Improve Dietary Assessment for Cardiovascular Disease
A study testing one 24 hr cycle of meals at a 2000 kcal level, one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage and one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage in people with Healthy Adults, run by University of California, San Diego at 1 site in United States.
Trial summary
In this research study, the investigators will use a novel approach to measure what people eat. The goal is to find out whether stable isotopes that can be measured in blood, hair, and fingernails are better at measuring what people eat than the surveys that are currently used. Read more about this study
- Who is it for?
- Ages 21 to 74 yearsHealthy volunteers can take part
- Conditions the study is for
- Healthy Adults
- What is being tested?
- one 24 hr cycle of meals at a 2000 kcal level, one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage and one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 0 participants
- Where
- 1 siteUnited States
- Study dates
- Aug 2021to Feb 2022
- Phase
- Interventional
- Are there results?
- None posted in the registry
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 21 to 74 years
- All sexes
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- men and women;
- aged 21 and 74 years;
- no history of chronic disease and in general good health;
- able to provide primary study outcome; and
- willing to tolerate study diets designed for controlled feeding.
Who cannot join
- recent dietary changes, restrictions, allergies or preferences;
- health conditions that require management beyond the scope of the study (e.g. heart failure, kidney disease, liver disease, gastrointestinal disorder);
- history of drug or alcohol abuse;
- plans to leave the San Diego area before study completion; and
- lack of suitability per investigators' discretion.
Trial locations and contacts
1 site in 1 country.
United States1 site
University of California, San Diego
San Diego, California, 92093
About this study
In this research study, the investigators will use a novel approach to measure what people eat. The goal is to find out whether stable isotopes that can be measured in blood, hair, and fingernails are better at measuring what people eat than the surveys that are currently used. To meet the goal, the investigators will do three things. First, the investigators will feed study participants known amounts of foods and nutrients. Second, after study participants have eaten the food, the investigators will measure stable isotopes in samples of study participants' blood, hair, and fingernails. Third, the investigators will determine how well these samples reflect what was eaten. The investigators will also give surveys to study participants to determine how well the surveys reflect what was eaten. This will allow the investigators to do a relative comparison of the measurements from isotopes and surveys.
Read the detailed description
This is a controlled feeding study in which the relative validity of stable carbon and nitrogen isotope ratio analysis as a biomarker of dietary intake is compared to controlled feedings and multiple 24-hour recalls. Participants will be randomly assigned to a sequence of diets to be fed on four occasions. Participants will undergo 24 hours of controlled feeding on four non-consecutive days over a month-long period. On the day after feeding, participants will complete 24-hour dietary recalls, and provide blood, hair, and fingernail samples for isotope ratio analyses. The investigators will use a crossover design and the diets will be either high or low in C4 plants (i.e., corn and cane products). A 24-hour urine collection will be done at home during each 24-hour feeding period. Participants will have height and weight measured at the screening visit. Weight will also be measured at each study visit. Additionally, data will be collected via questionnaires administered at each study visit.
- Conditions
- Healthy Adults
- Being tested
- one 24 hr cycle of meals at a 2000 kcal level, one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage, one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage, one 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverage
- Keywords
- Isotopes, Sugar, Diet, Health
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
one 24 hr cycle of meals at a 2000 kcal levelDietary supplement
50g added sugar
one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverageDietary supplement
90 grams added sugar
one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverageDietary supplement
130 grams added sugar
one 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverageDietary supplement
170 grams added sugar
| Study group | Role | What they receive |
|---|---|---|
| 50g added sugar | Experimental | Crossover design and each participant receives all 4 experimental arms/doses in random order Receives: Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level |
| 90g added sugar | Experimental | Crossover design and each participant receives all 4 experimental arms/doses in random order Receives: Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage |
| 130g added sugar | Experimental | Crossover design and each participant receives all 4 experimental arms/doses in random order Receives: Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage |
| 170g added sugar | Experimental | Crossover design and each participant receives all 4 experimental arms/doses in random order Receives: Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverage |
What is being measured
The primary outcome is the main question the study is designed to answer.
Carbon isotope values from blood
The ratio of carbon 13 to carbon 12 in human blood will be determined.
Measured: 30 days
Secondary outcomes (5)
Carbon isotope values from hair
The ratio of carbon 13 to carbon 12 in human hair samples will be determined.
Measured: 30 days
Carbon isotope values from fingernails
The ratio of carbon 13 to carbon 12 in human fingernail samples will be determined.
Measured: 30 days
Nitrogen isotope values from blood
The ratio of nitrogen-15 to nitrogen 14 in human blood will be determined.
Measured: 30 days
Nitrogen isotope values from hair
The ratio of nitrogen-15 to nitrogen 14 in human hair will be determined.
Measured: 30 days
Nitrogen isotope values from fingernails
The ratio of nitrogen-15 to nitrogen 14 in human fingernails will be determined.
Measured: 30 days
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted22 Jun 2021
- Study startAug 2021 (estimated)
- Primary completionFeb 2022 (estimated)
- Study completionFeb 2022 (estimated)
Why it stopped: Funding not renewed.
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Healthy AdultsStudies of the same condition, open and under way.
- More trials run by University of California, San DiegoThe sponsor's other registered studies.
- 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
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- Dietary intervention consisting of four 24-hour feeding periods (1 feeding period per week for 4 weeks).
- Masking
- Double blind
- Who is masked
- Participant, Care provider
- Enrolment
- 0 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of California, San Diego
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Cheryl A. Anderson, MPH, PhD, University of California, San Diego
- Investigators
- Cheryl A. Anderson, PhD, Principal investigator, University of California, San Diego
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04933656
- Sponsor's protocol ID
- 16IRG27770080
- Acronym
- I-CAN
- Status last verified
- Jan 2026
- First submitted
- 21 Feb 2020
- Last updated
- 26 Jan 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Study at a glance
From the registry record, last updated by the sponsor on 26 Jan 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Use of Stable Carbon And Nitrogen Isotopes to Improve Dietary Assessment for Cardiovascular Disease
- ClinicalTrials.gov ID
- NCT04933656
- Acronym / sponsor ID
- I-CAN / 16IRG27770080
- Conditions
- Healthy Adults
- Keywords
- Isotopes, Sugar, Diet, Health
- Study type
- Interventional
- Recruitment status
- WithdrawnReason stopped: Funding not renewed.
- Enrolment
- 0 participants (actual)
- Lead sponsor
- University of California, San DiegoUniversity, hospital or other
- Study start
- Aug 2021 (estimated)
- Primary completion
- Feb 2022 (estimated)
- Study completion
- Feb 2022 (estimated)
- First posted
- 22 Jun 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
In this research study, the investigators will use a novel approach to measure what people eat. The goal is to find out whether stable isotopes that can be measured in blood, hair, and fingernails are better at measuring what people eat than the surveys that are currently used. To meet the goal, the investigators will do three things. First, the investigators will feed study participants known amounts of foods and nutrients. Second, after study participants have eaten the food, the investigators will measure stable isotopes in samples of study participants' blood, hair, and fingernails. Third, the investigators will determine how well these samples reflect what was eaten. The investigators will also give surveys to study participants to determine how well the surveys reflect what was eaten. This will allow the investigators to do a relative comparison of the measurements from isotopes and surveys.
Detailed description
This is a controlled feeding study in which the relative validity of stable carbon and nitrogen isotope ratio analysis as a biomarker of dietary intake is compared to controlled feedings and multiple 24-hour recalls. Participants will be randomly assigned to a sequence of diets to be fed on four occasions. Participants will undergo 24 hours of controlled feeding on four non-consecutive days over a month-long period. On the day after feeding, participants will complete 24-hour dietary recalls, and provide blood, hair, and fingernail samples for isotope ratio analyses. The investigators will use a crossover design and the diets will be either high or low in C4 plants (i.e., corn and cane products). A 24-hour urine collection will be done at home during each 24-hour feeding period. Participants will have height and weight measured at the screening visit. Weight will also be measured at each study visit. Additionally, data will be collected via questionnaires administered at each study visit.
Study design
- Primary purpose
- Health services research
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Double blind (participant, care provider)
- Number of arms
- 4
- Model description
- Dietary intervention consisting of four 24-hour feeding periods (1 feeding period per week for 4 weeks).
| Arm | Type | Receives |
|---|---|---|
| 50g added sugar | Experimental | Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal levelCrossover design and each participant receives all 4 experimental arms/doses in random order |
| 90g added sugar | Experimental | Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverageCrossover design and each participant receives all 4 experimental arms/doses in random order |
| 130g added sugar | Experimental | Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverageCrossover design and each participant receives all 4 experimental arms/doses in random order |
| 170g added sugar | Experimental | Dietary Supplement: one 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverageCrossover design and each participant receives all 4 experimental arms/doses in random order |
Who may qualify
- Ages
- 21 to 74 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (5 listed)
- men and women;
- aged 21 and 74 years;
- no history of chronic disease and in general good health;
- able to provide primary study outcome; and
- willing to tolerate study diets designed for controlled feeding.
Key exclusion criteria (5 listed)
- recent dietary changes, restrictions, allergies or preferences;
- health conditions that require management beyond the scope of the study (e.g. heart failure, kidney disease, liver disease, gastrointestinal disorder);
- history of drug or alcohol abuse;
- plans to leave the San Diego area before study completion; and
- lack of suitability per investigators' discretion.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| one 24 hr cycle of meals at a 2000 kcal level50g added sugar | Dietary supplement | 50g added sugar |
| one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage90 grams added sugar | Dietary supplement | 90g added sugar |
| one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage130 grams added sugar | Dietary supplement | 130g added sugar |
| one 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverage170 grams added sugar | Dietary supplement | 170g added sugar |
Primary outcome
Carbon isotope values from blood
Time frame: 30 days
The ratio of carbon 13 to carbon 12 in human blood will be determined.
5 secondary outcomes
Carbon isotope values from hair
Time frame: 30 days
Carbon isotope values from fingernails
Time frame: 30 days
Nitrogen isotope values from blood
Time frame: 30 days
Nitrogen isotope values from hair
Time frame: 30 days
Nitrogen isotope values from fingernails
Time frame: 30 days
Results and safety
The study was withdrawn before enrolling participants, so there are no results.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 26 Jan 2026.
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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.
Cheryl A. Anderson, PhD principal investigator
University of California, San Diego
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing one 24 hr cycle of meals at a 2000 kcal level, one 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage and one 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage in people with Healthy Adults, run by University of California, San Diego 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 5 inclusion and 5 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: withdrawn, as of the sponsor's last update on 26 Jan 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?
The study was withdrawn before enrolling participants, so there are no results.
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?
Carbon isotope values from blood (time frame: 30 days). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
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 26 Jan 2026.