DigestibilityNCT04877262
Effects of Time-restricted Eating on Nutrient Absorption in Healthy Adults
A study testing weight maintenance diet (WMD) in people with Digestibility, run by Florida State University at 1 site in United States.
Trial summary
This 2-period, crossover, controlled-feeding trial will investigate the effects of early time-restricted eating (8am-2pm), compared to a control eating timeframe (8am-8pm), on energy and macronutrient digestibility, the thermic effect of food (TEF), postprandial blood metabolites, 24 h glucose concentrations, glycemic… Read more about this study
- Who is it for?
- Ages 20 to 45 yearsHealthy volunteers can take part
- Conditions the study is for
- Digestibility
- What is being tested?
- weight maintenance diet (WMD)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 17 participants
- Where
- 1 siteUnited States
- Study dates
- 1 Dec 2021to 10 Jun 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 20 to 45 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- 20-45 years old
- Normal weight or overweight (18.5 to 29.9 kg/m2)
- Not taking any probiotics for 4 weeks prior to and throughout the entire study
- Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the study
- Willing to consume a controlled diet for 9 consecutive days on 2 different occasions (18 days total) and collect all urine and fecal output for 3-5 days during each occasion
- Pass the blue dye gastrointestinal tracer (given at screening) within 72 hours of administration
Who cannot join
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, prior bariatric surgery, malabsorption, or any condition that interferes with metabolism (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Suspected or known strictures, fistulas, or physiological/mechanical gastrointestinal obstruction
- Present condition of alcoholism, anabolic steroids, or other substance abuse issues
- Women who are pregnant, lactating, planning to become pregnant, or who have an irregular menstrual cycle in the past 6 months
- Weight fluctuations ± 5% of body weight in the last 6 months
- Allergies or intolerance to foods included in the controlled diet
Show all 9Show fewer
- Any use of antibiotics, except topical antibiotics, within 3 months of study participation
- Colonoscopy within 3 months of study participation
- Use of laxatives, stool softeners, or anti-diarrheal medications more than once a week within 4-weeks of study enrollment
Trial locations and contacts
1 site in 1 country.
United States1 site
Florida State University
Tallahassee, Florida, 32306
About this study
This 2-period, crossover, controlled-feeding trial will investigate the effects of early time-restricted eating (8am-2pm), compared to a control eating timeframe (8am-8pm), on energy and macronutrient digestibility, the thermic effect of food (TEF), postprandial blood metabolites, 24 h glucose concentrations, glycemic variability, intestinal hydrogen gas production, gastrointestinal transit time, and microbiome composition. This study will also seek to determine factors that may predict intestinal absorption efficiency (i.e., digestibility) including the microbial composition of stool, fasting and postprandial metabolomics, gastrointestinal transit time, thermic effect of food, 24 h glucose concentrations and variability, and hydrogen gas production.
Read the detailed description
The obesity epidemic is well documented, and despite a complex etiology influenced by genetic, physiological, psychological, social, behavioral, and environmental factors, obesity seems to be the result of energy imbalance, where energy intake exceeds energy expenditure, regardless of the internal and external influences. Studies aiming to quantify and manipulate modulators of energy balance, including gastrointestinal (GI) energy absorption rates (i.e., digestibility), are crucial for reducing the incidence of overweight and obesity and improving overall human health. Despite considerable interindividual variability in the amount of ingested energy that is absorbed (~87-98% of ingested energy) by the gastrointestinal tract, generalized equations are used to calculate individual energy intake requirements, and the factors that contribute to such variability, including meal-timing, are largely unknown.
The proposed study seeks to determine the effects of restricting the eating window to 6-h (early time-restricted eating) as compared to a control eating window of 12 h on energy and macronutrient digestibility, thermic effect of food (TEF), postprandial blood metabolites (triglyceride, insulin, glucose, fructose, galactose, inositol, and sorbitol), 24 h glucose concentrations and glycemic variability, intestinal hydrogen gas production, microbiome composition, and gastrointestinal transit time in response to a controlled, energy balanced diet. In addition, this project will determine whether energy digestibility can be predicted from biological and physiological factors such as gut microbiota composition, gastrointestinal transit time, 24-h glucose concentrations, and postabsorptive and postprandial metabolomic profiles.
Participants will be randomized to early TRE (6-h feeding window, 8am-2pm) or a control eating schedule (12-h feeding window, 8am-8pm) and consume a controlled, energy balance diet (breakfast, lunch, dinner, snacks, and beverages) for 9 consecutive days before crossing over to the other intervention after at least a 3-wk washout for females (to control for hormonal fluctuations) and at least a 2-wk washout for males. Participants will collect stool and urine during each feeding phase. Gross energy content (heat combustion by bomb calorimetry) of the diet, stool, and urine samples will be used to calculate energy digestibility (diet gross energy - stool gross energy) and metabolizable energy. Factors that may mediate and/or predict energy digestibility efficiency, including gastrointestinal microbial composition, transit time, and gas production, fasting and postprandial metabolites, continuous glucose concentrations, and thermogenesis will be assessed.
- Conditions
- Digestibility
- Being tested
- weight maintenance diet (WMD)
- Keywords
- stool energy loss, digestibility, intestinal absorption, overweight, microbiome, metabolomics, energy balance
- Medical subject headings
- Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
weight maintenance diet (WMD)Other
A diet meeting the participant's weight maintenance energy needs will be provided.
| Study group | Role | What they receive |
|---|---|---|
| early time-restricted eating (eTRE) | Experimental | Participants will be provided a weight-maintenance diet for 9 consecutive days and will consume all meals and snacks in a 6-h window in the morning hours (e.g., 8:00 AM - 2:00 PM) Receives: Other: weight maintenance diet (WMD) |
| control eating schedule (CON) | Experimental | Participants will be provided a weight-maintenance diet for 9 consecutive days and will consume all meals and snacks in a 12-h window in the morning hours (e.g., 8:00 AM - 8:00 PM) Receives: Other: weight maintenance diet (WMD) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Energy digestibility
Calculated as gross energy of the diet (kcals) - gross energy excreted in stool (kcals)
Measured: Days 4-9
Secondary outcomes (13)
Fat digestibility
Calculated as fat content of the diet - fat content excreted in stool
Measured: Days 4-9
Carbohydrate digestibility
Calculated as carbohydrate content of the diet - carbohydrate content excreted in stool
Measured: Days 4-9
Protein digestibility
Calculated as protein content of the diet - protein content excreted in stool
Measured: Days 4-9
Metabolizable energy
Calculated as gross energy of the diet (kcals) - gross energy excreted in urine and stool (kcals)
Measured: Days 4-9
Metabolizable protein
Calculated as protein content of the diet - protein excreted in urine and stool
Measured: Days 4-9
Postabsorptive and postprandial plasma metabolites
Plasma metabolites will be measured using gas chromatography coupled with mass spectrometry in the postabsorptive state and following a standardized meal (1 hour, 2 hours, 3 hours, and 4 hours after meal intake).
Measured: Day 6
Gut microbiome
Microbiota composition and diversity will be determined using 16S rRNA gene sequencing.
Measured: Day 6
Gastrointestinal transit time
A gas-sensing capsule will be ingested to measure transit time in the gastrointestinal tract.
Measured: Day 6
Gastrointestinal gas production
A gas-sensing capsule will be ingested to measure hydrogen, carbon dioxide, and oxygen production in the gastrointestinal tract.
Measured: Day 6
Gastrointestinal temperature
A gas-sensing capsule will be ingested to measure temperature in the gastrointestinal tract.
Measured: Day 6
24-h glucose concentrations
A continuous glucose monitor will be used to collect and assess 24-h glucose concentrations.
Measured: Days 1-8
24-h glucose variability
A continuous glucose monitor will be used to collect and assess 24-h glucose variability.
Measured: Days 1-8
Thermic effect of food
Indirect calorimetry measures will be collected in the resting state and for 4 hours (15-30, 45-60, 75-90, 105-120, 165-180, and 225-240 minutes) following the consumption of a standardized meal.
Measured: Day 6
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted7 May 2021
- Study start1 Dec 2021
- Primary completion10 Jun 2022
- Study completion10 Jun 2022
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (2)Papers the sponsor has linked to this study.
- Other trials for DigestibilityStudies of the same condition, open and under way.
- More trials run by Florida State UniversityThe 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
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Model description
- The study is a randomized, crossover, controlled feeding study design consisting of two 9-d weight maintenance diet periods separated by at least 3 weeks.
- Masking
- None (open label)
- Enrolment
- 17 participants (actual)
Sponsor and investigators
- Lead sponsor
- Florida State University
- Sponsor type
- University, hospital or other
- Responsible party
- Principal investigator, Claire E. Berryman, Florida State University
- Investigators
- Claire E Berryman, Ph.D., Principal investigator, Florida State University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04877262
- Sponsor's protocol ID
- STUDY00001564
- Status last verified
- Jun 2022
- First submitted
- 14 Mar 2021
- Last updated
- 23 Jun 2022
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No
Publications
Dawson MA, Cheung SN, La Frano MR, Nagpal R, Berryman CE. Intestinal Energy Absorption Is Associated with Glycemic Variability in Young, Healthy Adults. J Nutr. 2025 Jul;155(7):2205-2214. doi: 10.1016/j.tjnut.2025.05.018. Epub 2025 May 23.
PubMed 40414300Dawson MA, Cheung SN, La Frano MR, Nagpal R, Berryman CE. Early time-restricted eating improves markers of cardiometabolic health but has no impact on intestinal nutrient absorption in healthy adults. Cell Rep Med. 2024 Jan 16;5(1):101363. doi: 10.1016/j.xcrm.2023.101363.
PubMed 38232698
Study at a glance
From the registry record, last updated by the sponsor on 23 Jun 2022. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effects of Time-restricted Eating on Nutrient Absorption in Healthy Adults
- ClinicalTrials.gov ID
- NCT04877262
- Acronym / sponsor ID
- STUDY00001564
- Conditions
- Digestibility
- Keywords
- stool energy loss, digestibility, intestinal absorption, overweight, microbiome, metabolomics, energy balance
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 17 participants (actual)
- Lead sponsor
- Florida State UniversityUniversity, hospital or other
- Study start
- 1 Dec 2021 (actual)
- Primary completion
- 10 Jun 2022 (actual)
- Study completion
- 10 Jun 2022 (actual)
- First posted
- 7 May 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.
This 2-period, crossover, controlled-feeding trial will investigate the effects of early time-restricted eating (8am-2pm), compared to a control eating timeframe (8am-8pm), on energy and macronutrient digestibility, the thermic effect of food (TEF), postprandial blood metabolites, 24 h glucose concentrations, glycemic variability, intestinal hydrogen gas production, gastrointestinal transit time, and microbiome composition. This study will also seek to determine factors that may predict intestinal absorption efficiency (i.e., digestibility) including the microbial composition of stool, fasting and postprandial metabolomics, gastrointestinal transit time, thermic effect of food, 24 h glucose concentrations and variability, and hydrogen gas production.
Detailed description
The obesity epidemic is well documented, and despite a complex etiology influenced by genetic, physiological, psychological, social, behavioral, and environmental factors, obesity seems to be the result of energy imbalance, where energy intake exceeds energy expenditure, regardless of the internal and external influences. Studies aiming to quantify and manipulate modulators of energy balance, including gastrointestinal (GI) energy absorption rates (i.e., digestibility), are crucial for reducing the incidence of overweight and obesity and improving overall human health. Despite considerable interindividual variability in the amount of ingested energy that is absorbed (~87-98% of ingested energy) by the gastrointestinal tract, generalized equations are used to calculate individual energy intake requirements, and the factors that contribute to such variability, including meal-timing, are largely unknown.
The proposed study seeks to determine the effects of restricting the eating window to 6-h (early time-restricted eating) as compared to a control eating window of 12 h on energy and macronutrient digestibility, thermic effect of food (TEF), postprandial blood metabolites (triglyceride, insulin, glucose, fructose, galactose, inositol, and sorbitol), 24 h glucose concentrations and glycemic variability, intestinal hydrogen gas production, microbiome composition, and gastrointestinal transit time in response to a controlled, energy balanced diet. In addition, this project will determine whether energy digestibility can be predicted from biological and physiological factors such as gut microbiota composition, gastrointestinal transit time, 24-h glucose concentrations, and postabsorptive and postprandial metabolomic profiles.
Participants will be randomized to early TRE (6-h feeding window, 8am-2pm) or a control eating schedule (12-h feeding window, 8am-8pm) and consume a controlled, energy balance diet (breakfast, lunch, dinner, snacks, and beverages) for 9 consecutive days before crossing over to the other intervention after at least a 3-wk washout for females (to control for hormonal fluctuations) and at least a 2-wk washout for males. Participants will collect stool and urine during each feeding phase. Gross energy content (heat combustion by bomb calorimetry) of the diet, stool, and urine samples will be used to calculate energy digestibility (diet gross energy - stool gross energy) and metabolizable energy. Factors that may mediate and/or predict energy digestibility efficiency, including gastrointestinal microbial composition, transit time, and gas production, fasting and postprandial metabolites, continuous glucose concentrations, and thermogenesis will be assessed.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
- Model description
- The study is a randomized, crossover, controlled feeding study design consisting of two 9-d weight maintenance diet periods separated by at least 3 weeks.
| Arm | Type | Receives |
|---|---|---|
| early time-restricted eating (eTRE) | Experimental | Other: weight maintenance diet (WMD)Participants will be provided a weight-maintenance diet for 9 consecutive days and will consume all meals and snacks in a 6-h window in the morning hours (e.g., 8:00 AM - 2:00 PM) |
| control eating schedule (CON) | Experimental | Other: weight maintenance diet (WMD)Participants will be provided a weight-maintenance diet for 9 consecutive days and will consume all meals and snacks in a 12-h window in the morning hours (e.g., 8:00 AM - 8:00 PM) |
Who may qualify
- Ages
- 20 to 45 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- 20-45 years old
- Normal weight or overweight (18.5 to 29.9 kg/m2)
- Not taking any probiotics for 4 weeks prior to and throughout the entire study
- Willing to refrain from smoking, vaping, chewing tobacco, and dietary supplement use throughout the study
- Willing to consume a controlled diet for 9 consecutive days on 2 different occasions (18 days total) and collect all urine and fecal output for 3-5 days during each occasion
Key exclusion criteria (9 listed)
- Metabolic or cardiovascular abnormalities, gastrointestinal disorders, prior bariatric surgery, malabsorption, or any condition that interferes with metabolism (e.g., kidney disease, diabetes, cardiovascular disease, etc.)
- Suspected or known strictures, fistulas, or physiological/mechanical gastrointestinal obstruction
- Present condition of alcoholism, anabolic steroids, or other substance abuse issues
- Women who are pregnant, lactating, planning to become pregnant, or who have an irregular menstrual cycle in the past 6 months
- Weight fluctuations ± 5% of body weight in the last 6 months
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 |
|---|---|---|
| weight maintenance diet (WMD)A diet meeting the participant's weight maintenance energy needs will be provided. | Other | control eating schedule (CON), early time-restricted eating (eTRE) |
Primary outcome
Energy digestibility
Time frame: Days 4-9
Calculated as gross energy of the diet (kcals) - gross energy excreted in stool (kcals)
13 secondary outcomes
Fat digestibility
Time frame: Days 4-9
Carbohydrate digestibility
Time frame: Days 4-9
Protein digestibility
Time frame: Days 4-9
Metabolizable energy
Time frame: Days 4-9
Metabolizable protein
Time frame: Days 4-9
Postabsorptive and postprandial plasma metabolites
Time frame: Day 6
Gut microbiome
Time frame: Day 6
Gastrointestinal transit time
Time frame: Day 6
Gastrointestinal gas production
Time frame: Day 6
Gastrointestinal temperature
Time frame: Day 6
24-h glucose concentrations
Time frame: Days 1-8
24-h glucose variability
Time frame: Days 1-8
Thermic effect of food
Time frame: Day 6
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 23 Jun 2022.
- Derived from this study: PubMed 40414300Dawson MA, Cheung SN, La Frano MR, Nagpal R, Berryman CE. Intestinal Energy Absorption Is Associated with Glycemic Variability in Young, Healthy Adults. J Nutr. 2025 Jul;155(7):2205-2214. doi: 10.1016/j.tjnut.2025.05.018. Epub 2025 May 23.
- Derived from this study: PubMed 38232698Dawson MA, Cheung SN, La Frano MR, Nagpal R, Berryman CE. Early time-restricted eating improves markers of cardiometabolic health but has no impact on intestinal nutrient absorption in healthy adults. Cell Rep Med. 2024 Jan 16;5(1):101363. doi: 10.1016/j.xcrm.2023.101363.
- Individual participant dataSharing planned: No
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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.
Claire E Berryman, Ph.D. principal investigator
Florida State University
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing weight maintenance diet (WMD) in people with Digestibility, run by Florida State University 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 6 inclusion and 9 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 23 Jun 2022. 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 is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
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 digestibility (time frame: Days 4-9). 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 NCT04877262, which also lists 2 linked publications.
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 23 Jun 2022.