The CLOCK Study - A Human Dietary Intervention Study on Peripheral Circadian Clocks and Energy Metabolism

Study Overview
=================
Brief 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.

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.

Official Title
-----------------
Interplay of Peripheral Circadian Clocks With Energy Balance and Body Weight Regulation

Conditions
-----------------
Metabolic Response to Dietary Modification

Intervention / Treatment
-----------------
* Other: Carbohydrate-rich (HC)
* Other: Fat-rich (HF)


Participation Criteria
=================
Eligibility Criteria
-----------------
Inclusion Criteria: 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 Exclusion Criteria: 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 Men unable to give an informed consent Men unable to engage in the dietary interventions Men following a special diet

Ages Eligible for Study
-----------------
Minimum Age: 18 Years
Maximum Age: 70 Years

Sexes Eligible for Study
-----------------
Male

Accepts Healthy Volunteers
-----------------
Accepts Healthy Volunteers

Study Plan
=================
How is the study designed?
-----------------

Design Details

Primary Purpose: Basic Science
Allocation: Randomized
Intervention Model: Crossover Assignment
Masking: None (Open Label)


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Other: Carbohydrate-rich_Fat-rich (HC_HF)<br>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 | Other: Carbohydrate-rich (HC)<br>* 65% Carbohydrate; 20% Fat; 15% Protein<br>Other: Fat-rich (HF)<br>* 35% Carbohydrate; 50% Fat; 15% Protein<br>|
| Other: Fat-rich_Carbohydrate-rich (HF_HC)<br>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 | Other: Carbohydrate-rich (HC)<br>* 65% Carbohydrate; 20% Fat; 15% Protein<br>Other: Fat-rich (HF)<br>* 35% Carbohydrate; 50% Fat; 15% Protein<br>|

What is the study measuring?
-----------------
Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dietary-induced changes of glucose and lipid metabolism |  | week 4 | 
| Effect of different diurnal patterns of meal composition on peripheral circadian clocks in blood cells and subcutaneous adipose tissue |  | week 4 | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Dietary-induced changes of satiety and hunger scores | Measured via visual analogue scales | week 4 | 
| Effect of different diurnal patterns of meal composition on Lipopolysaccharide-induced cytokine expression |  | week 4 | 
| Dietary-induced changes of the human adipose tissue lipidome |  | week 4 | 
| Integrative analysis of dietary-induced changes of the human adipose tissue transcriptome | Microarray Analysis of adipose tissue samples | week 4 |