Healthy Adults
Conditions
Keywords
Isotopes, Sugar, Diet, Health
Brief 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. 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.
Interventions
DIETARY_SUPPLEMENTone 24 hr cycle of meals at a 2000 kcal level
50g added sugar
DIETARY_SUPPLEMENTone 24 hr cycle of meals at a 2000 kcal level + one serving sugar sweetened beverage
90 grams added sugar
DIETARY_SUPPLEMENTone 24 hr cycle of meals at a 2000 kcal level + two servings sugar sweetened beverage
130 grams added sugar
DIETARY_SUPPLEMENTone 24 hr cycle of meals at a 2000 kcal level + three serving sugar sweetened beverage
170 grams added sugar
Sponsors
University of California, San Diego
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
HEALTH_SERVICES_RESEARCH
Masking
DOUBLE (Subject, Caregiver)
Masking description
Double blinding: Participant and person collecting data measurement.
Intervention model description
Dietary intervention consisting of four 24-hour feeding periods (1 feeding period per week for 4 weeks).
Eligibility
Sex/Gender
ALL
Age
21 Years to 74 Years
Healthy volunteers
Yes
Inclusion criteria
* 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.
Exclusion criteria
* 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.
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Carbon isotope values from blood | 30 days | The ratio of carbon 13 to carbon 12 in human blood will be determined. |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Carbon isotope values from hair | 30 days | The ratio of carbon 13 to carbon 12 in human hair samples will be determined. |
| Carbon isotope values from fingernails | 30 days | The ratio of carbon 13 to carbon 12 in human fingernail samples will be determined. |
| Nitrogen isotope values from blood | 30 days | The ratio of nitrogen-15 to nitrogen 14 in human blood will be determined. |
| Nitrogen isotope values from hair | 30 days | The ratio of nitrogen-15 to nitrogen 14 in human hair will be determined. |
| Nitrogen isotope values from fingernails | 30 days | The ratio of nitrogen-15 to nitrogen 14 in human fingernails will be determined. |
Countries
United States
Contacts
PRINCIPAL_INVESTIGATORCheryl A. Anderson, PhD
University of California, San Diego
Outcome results
None listed