Metabolic Response to Dietary ModificationCLOCKNCT02487576
The CLOCK Study - A Human Dietary Intervention Study on Peripheral Circadian Clocks and Energy Metabolism
A study testing Carbohydrate-rich (HC) and Fat-rich (HF) in people with Metabolic Response to Dietary Modification, run by German Institute of Human Nutrition at 1 site in Germany.
Trial summary
This human dietary intervention study with a cross-over design aims to investigate the effect of two different diurnal patterns of meal composition on peripheral circadian clocks and energy metabolism in healthy men. Read more about this study
- Who is it for?
- Ages 18 to 70 years, men onlyHealthy volunteers can take part
- Conditions the study is for
- Metabolic Response to Dietary Modification
- What is being tested?
- Carbohydrate-rich (HC) and Fat-rich (HF)
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 32 participants
- Where
- 1 siteGermany
- Study dates
- Jan 2014to Aug 2015
- 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 18 to 70 years
- Men only
- Healthy volunteers accepted
- Adult, Older adult
Who may be able to join
- BMI between 22 kg/m² and 34,9 kg/m²
- Normal glucose tolerance determined in a 75g-oral glucose tolerance test
- Impaired fasting glucose determined in a 75g-oral glucose tolerance test
- Impaired glucose tolerance determined in a 75g-oral glucose tolerance test
Who cannot join
- Shift workers or history of shift work
- Men suffering from diseases or conditions that might influence the outcome of the study. Of special interest are diseases that influence body weight regulation (enteropathy, malabsorption, hepatopathy, renal disease, endocrine disorders, diabetes mellitus, eating disorders, heart disease etc.). Also men suffering from coagulopathy, apoplexy and myocardial infarction are excluded from the study.
- Men suffering from psychiatric disease
- Planned changes in physical activity during the study
- Participation in other clinical studies within the last three months
- Weight changes > 2 kg within 2 months prior to screening day
Show all 9Show fewer
- Men unable to give an informed consent
- Men unable to engage in the dietary interventions
- Men following a special diet
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Interplay of Peripheral Circadian Clocks With Energy Balance and Body Weight Regulation
This human dietary intervention study with a cross-over design aims to investigate the effect of two different diurnal patterns of meal composition on peripheral circadian clocks and energy metabolism in healthy men.
Read the detailed description
In this cross-over study, healthy male participants are randomly allocated to one of two study groups: In study group (A) participants consume isocaloric carbohydrate-rich meals (65% Carbohydrates; 20% Fat; 15% Protein) in the morning and fat-rich meals (35% Carbohydrate; 50% Fat; 15% Protein) in the evening for four weeks. After a washout-phase participants consume isocaloric fat-rich meals in the morning and carbohydrate-rich meals in the evening for another four weeks. Study group (B) receives the same interventions in the reversed order.
- Being tested
- Carbohydrate-rich (HC), Fat-rich (HF)
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Carbohydrate-rich (HC)Other
65% Carbohydrate; 20% Fat; 15% Protein
Fat-rich (HF)Other
35% Carbohydrate; 50% Fat; 15% Protein
| Study group | Role | What they receive |
|---|---|---|
| Carbohydrate-rich_Fat-rich (HC_HF) | Other | Isocaloric carbohydrate-rich meals in the morning (06.00 am - 01.30 pm) and isocaloric fat-rich meals in the evening (04.30 pm - 10.00 pm) for 4 weeks |
| Fat-rich_Carbohydrate-rich (HF_HC) | Other | Isocaloric fat-rich meals in the morning (06.00 am - 01.30 pm) and isocaloric carbohydrate-rich meals in the evening (04.30 pm - 10.00 pm) for 4 weeks Receives: Other: Carbohydrate-rich (HC); Other: Fat-rich (HF) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Dietary-induced changes of glucose and lipid metabolism
Measured: week 4
Effect of different diurnal patterns of meal composition on peripheral circadian clocks in blood cells and subcutaneous adipose tissue
Measured: week 4
Secondary outcomes (4)
Dietary-induced changes of satiety and hunger scores
Measured via visual analogue scales
Measured: week 4
Effect of different diurnal patterns of meal composition on Lipopolysaccharide-induced cytokine expression
Measured: week 4
Dietary-induced changes of the human adipose tissue lipidome
Measured: week 4
Integrative analysis of dietary-induced changes of the human adipose tissue transcriptome
Microarray Analysis of adipose tissue samples
Measured: week 4
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted1 Jul 2015 (estimated)
- Study startJan 2014
- Primary completionJul 2015
- Study completionAug 2015
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (4)Papers the sponsor has linked to this study.
- Other trials for Metabolic Response to Dietary ModificationStudies of the same condition, open and under way.
- 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
- Masking
- None (open label)
- Enrolment
- 32 participants (actual)
Sponsor and investigators
- Lead sponsor
- German Institute of Human Nutrition
- Sponsor type
- University, hospital or other
- Collaborators
- German Federal Ministry of Education and Research, Charite University, Berlin, Germany, Heidelberg University, Max-Planck Institute of Molecular Cell Biology and Genetics
- Responsible party
- Principal investigator, Prof. Dr. med. Andreas F. H. Pfeiffer, German Institute of Human Nutrition
- Investigators
- Andreas FH Pfeiffer, Prof. Dr., Study director, German Institute of Human Nutrition
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT02487576
- Sponsor's protocol ID
- DFG grant KFO218 PF164/16-1
- Other IDs
- DDG021023
- Acronym
- CLOCK
- Status last verified
- Aug 2025
- First submitted
- 28 May 2015
- Last updated
- 26 Aug 2025
- Results posted
- No
- Data monitoring committee
- No
Publications
Kessler K, Hornemann S, Petzke KJ, Kemper M, Kramer A, Pfeiffer AF, Pivovarova O, Rudovich N. The effect of diurnal distribution of carbohydrates and fat on glycaemic control in humans: a randomized controlled trial. Sci Rep. 2017 Mar 8;7:44170. doi: 10.1038/srep44170.
PubMed 28272464Kessler K, Hornemann S, Petzke KJ, Kemper M, Markova M, Rudovich N, Grune T, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Diurnal distribution of carbohydrates and fat affects substrate oxidation and adipokine secretion in humans. Am J Clin Nutr. 2018 Dec 1;108(6):1209-1219. doi: 10.1093/ajcn/nqy224.
PubMed 30541098Kessler K, Gerl MJ, Hornemann S, Damm M, Klose C, Petzke KJ, Kemper M, Weber D, Rudovich N, Grune T, Simons K, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Shotgun Lipidomics Discovered Diurnal Regulation of Lipid Metabolism Linked to Insulin Sensitivity in Nondiabetic Men. J Clin Endocrinol Metab. 2020 May 1;105(5):dgz176. doi: 10.1210/clinem/dgz176.
PubMed 31680138Kessler K, Hornemann S, Rudovich N, Weber D, Grune T, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Saliva Samples as A Tool to Study the Effect of Meal Timing on Metabolic And Inflammatory Biomarkers. Nutrients. 2020 Jan 28;12(2):340. doi: 10.3390/nu12020340.
PubMed 32013045
Study at a glance
From the registry record, last updated by the sponsor on 26 Aug 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Interplay of Peripheral Circadian Clocks With Energy Balance and Body Weight Regulation
- ClinicalTrials.gov ID
- NCT02487576
- Acronym / sponsor ID
- CLOCK / DFG grant KFO218 PF164/16-1
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 32 participants (actual)
- Lead sponsor
- German Institute of Human NutritionUniversity, hospital or other
- Collaborators
- German Federal Ministry of Education and Research, Charite University, Berlin, Germany, Heidelberg University, Max-Planck Institute of Molecular Cell Biology and Genetics
- Study start
- Jan 2014
- Primary completion
- Jul 2015 (actual)
- Study completion
- Aug 2015 (actual)
- First posted
- 1 Jul 2015 (estimated)
- 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 human dietary intervention study with a cross-over design aims to investigate the effect of two different diurnal patterns of meal composition on peripheral circadian clocks and energy metabolism in healthy men.
Detailed description
In this cross-over study, healthy male participants are randomly allocated to one of two study groups: In study group (A) participants consume isocaloric carbohydrate-rich meals (65% Carbohydrates; 20% Fat; 15% Protein) in the morning and fat-rich meals (35% Carbohydrate; 50% Fat; 15% Protein) in the evening for four weeks. After a washout-phase participants consume isocaloric fat-rich meals in the morning and carbohydrate-rich meals in the evening for another four weeks. Study group (B) receives the same interventions in the reversed order.
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Carbohydrate-rich_Fat-rich (HC_HF) | Other | –Isocaloric carbohydrate-rich meals in the morning (06.00 am - 01.30 pm) and isocaloric fat-rich meals in the evening (04.30 pm - 10.00 pm) for 4 weeks |
| Fat-rich_Carbohydrate-rich (HF_HC) | Other | Other: Carbohydrate-rich (HC), Other: Fat-rich (HF)Isocaloric fat-rich meals in the morning (06.00 am - 01.30 pm) and isocaloric carbohydrate-rich meals in the evening (04.30 pm - 10.00 pm) for 4 weeks |
Who may qualify
- Ages
- 18 to 70 years
- Sex
- Male only
- Healthy volunteers
- Accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (4 listed)
- BMI between 22 kg/m² and 34,9 kg/m²
- Normal glucose tolerance determined in a 75g-oral glucose tolerance test
- Impaired fasting glucose determined in a 75g-oral glucose tolerance test
- Impaired glucose tolerance determined in a 75g-oral glucose tolerance test
Key exclusion criteria (9 listed)
- Shift workers or history of shift work
- Men suffering from diseases or conditions that might influence the outcome of the study. Of special interest are diseases that influence body weight regulation (enteropathy, malabsorption, hepatopathy, renal disease, endocrine disorders, diabetes mellitus, eating disorders, heart disease etc.). Also men suffering from coagulopathy, apoplexy and myocardial infarction are excluded from the study.
- Men suffering from psychiatric disease
- Planned changes in physical activity during the study
- Participation in other clinical studies within the last three 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 |
|---|---|---|
| Carbohydrate-rich (HC)65% Carbohydrate; 20% Fat; 15% Protein | Other | Fat-rich_Carbohydrate-rich (HF_HC) |
| Fat-rich (HF)35% Carbohydrate; 50% Fat; 15% Protein | Other | Fat-rich_Carbohydrate-rich (HF_HC) |
Primary outcome
Dietary-induced changes of glucose and lipid metabolism
Time frame: week 4
Effect of different diurnal patterns of meal composition on peripheral circadian clocks in blood cells and subcutaneous adipose tissue
Time frame: week 4
4 secondary outcomes
Dietary-induced changes of satiety and hunger scores
Time frame: week 4
Effect of different diurnal patterns of meal composition on Lipopolysaccharide-induced cytokine expression
Time frame: week 4
Dietary-induced changes of the human adipose tissue lipidome
Time frame: week 4
Integrative analysis of dietary-induced changes of the human adipose tissue transcriptome
Time frame: week 4
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 26 Aug 2025.
- Results publication: PubMed 28272464Kessler K, Hornemann S, Petzke KJ, Kemper M, Kramer A, Pfeiffer AF, Pivovarova O, Rudovich N. The effect of diurnal distribution of carbohydrates and fat on glycaemic control in humans: a randomized controlled trial. Sci Rep. 2017 Mar 8;7:44170. doi: 10.1038/srep44170.
- Results publication: PubMed 30541098Kessler K, Hornemann S, Petzke KJ, Kemper M, Markova M, Rudovich N, Grune T, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Diurnal distribution of carbohydrates and fat affects substrate oxidation and adipokine secretion in humans. Am J Clin Nutr. 2018 Dec 1;108(6):1209-1219. doi: 10.1093/ajcn/nqy224.
- Results publication: PubMed 31680138Kessler K, Gerl MJ, Hornemann S, Damm M, Klose C, Petzke KJ, Kemper M, Weber D, Rudovich N, Grune T, Simons K, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Shotgun Lipidomics Discovered Diurnal Regulation of Lipid Metabolism Linked to Insulin Sensitivity in Nondiabetic Men. J Clin Endocrinol Metab. 2020 May 1;105(5):dgz176. doi: 10.1210/clinem/dgz176.
- Results publication: PubMed 32013045Kessler K, Hornemann S, Rudovich N, Weber D, Grune T, Kramer A, Pfeiffer AFH, Pivovarova-Ramich O. Saliva Samples as A Tool to Study the Effect of Meal Timing on Metabolic And Inflammatory Biomarkers. Nutrients. 2020 Jan 28;12(2):340. doi: 10.3390/nu12020340.
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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.
Andreas FH Pfeiffer, Prof. Dr. study director
German Institute of Human Nutrition
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Carbohydrate-rich (HC) and Fat-rich (HF) in people with Metabolic Response to Dietary Modification, run by German Institute of Human Nutrition at 1 site in Germany.
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 4 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 26 Aug 2025. 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 Germany. 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?
Dietary-induced changes of glucose and lipid metabolism (time frame: week 4). The study lists 2 primary outcomes in all. 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 NCT02487576, which also lists 4 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 26 Aug 2025.