Timing of Caloric Intake, Diet-induced Thermogenesis and Hormonal Pattern

Study Overview
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Brief Summary
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The investigators aim at analyzing whether eating a standard meal in the evening (at 8:00 pm) determines in the same individuals a lower diet-induced thermogenesis (DIT) and a different hormonal response than the consumption of the same meal in the morning (at 8:00 am). The primary outcome is: the intra-individual variation in DIT after the evening and morning meal consumption. The secondary outcomes are the intra-individual variations in glucose, triglyceride, insulin, free fatty acids, leptin, glucagon-like peptide-1, acylated ghrelin, adrenalin, noradrenalin, after the evening and morning meal consumption.

Detailed Description
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Twenty healthy volunteers (ten males and ten females) are recruited among students and graduates attending the Department of Medical Sciences of Turin (Italy) to take part to this randomized cross-over trial. Participants randomly receive first the standard meal at 8:00 am and the week after the standard meal at 8:00 pm or vice versa. Eight-h before the meal (respectively at 12:00 pm or at 12:00 am), the participants receive the same standard meal (without protein supplementation) at their home, and then are asked to spend in bed the following 6 hours. A 24-h urine collection is collected the day before each test in order to determine total urinary nitrogen excretion. The standard meal consists of: 100g white bread, 100g ham, 50g cheese, 125g yogurt, 200ml fruit juice, plus 25g protein supplement. The participants must consume each meal in 25-30 minutes. A 30-min basal calorimetric (Deltatrac II) exam is performed. Participants remain in a supine position but awake and motionless on a hospital bed during the whole period, except during the meal, when they can sit to eat. At 8:00 am (or pm), the participants consume the meal, and then rest in a supine position for 90 min. Then, a second 60 min-calorimetric evaluation is done. From the first calorimetric exam (the basal) until the end of the second (post-prandial) blood samples are drawn every 30 min. The same time schedule is adopted in the case of the morning meal (at 8:00 am) and the evening meal (at 8:00 pm). The random sequence (morning/evening, evening/morning meal) is computer-generated, using blocks of different lengths in random order. The following are measured: weight, height, waist circumference, and at baseline and every 30-min during the morning and evening tests: glucose, triglyceride, insulin, free-fatty acids, leptin, glucagon-like peptide-1, acylated ghrelin, adrenalin, noradrenalin.

Official Title
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Is the Timing of Caloric Intake Associated With Variation in Diet-induced Thermogenesis and Hormonal Pattern?

Conditions
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Diet-induced Thermogenesis

Intervention / Treatment
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* Other: calorimetric exam after a standard meal


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: body mass index 19-26 kg/m2 habitual moderate exercise level Exclusion Criteria: any acute or chronic diseases menopause any drugs or supplementations any alimentary restrictions or specific diets being a shift or night workers unable to give a written informed consent

Ages Eligible for Study
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Minimum Age: 20 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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All

Accepts Healthy Volunteers
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Accepts Healthy Volunteers

Study Plan
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How is the study designed?
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Design Details

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


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: morning-first<br>calorimetric exam after a standard meal | Other: calorimetric exam after a standard meal<br>* The calorimetric and metabolic responses to identical meals (a high-protein, low-carbohydrates meal) consumed in the morning (8:00 am) and in the evening (8:00 pm) are measured in healthy volunteers, after standardizing diet, physical activity level, duration of fast and resting<br>|
| Experimental: evening-first<br>calorimetric exam after a standard meal | Other: calorimetric exam after a standard meal<br>* The calorimetric and metabolic responses to identical meals (a high-protein, low-carbohydrates meal) consumed in the morning (8:00 am) and in the evening (8:00 pm) are measured in healthy volunteers, after standardizing diet, physical activity level, duration of fast and resting<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Intra-individual Variation in Morning Diet-induced Thermogenesis (DIT) Evaluated by Calorimetric Exam After the Consumption of a Meal at 8:00 am Compared With Evening DIT Evaluated by Calorimetric Exam After the Consumption of the Same Meal at 8:00 pm | Indirect calorimetry by Deltatrac II (DATEX, Division of Instruments Corp. Helsinki, Finland) is used to measure the rate of energy expenditure before- and after- the meal.Diet-induced thermogenesis is considered as the difference between average after-meal and basal energy expenditure. | Before and 180-min from the beginning of the meal | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Variation in Morning Glucose and Insulin Area-Under the Curve (AUC)s After the Consumption of a Meal at 8:00 am Compared With Evening Glucose and Insulin AUCs After the Consumption of the Same Meal at 8:00 pm | Glucose and insulin values measured every 30 minutes after meal for 180-min. Time 0 was before the meal. Times 30, 60, 90, 120, 150 and 180 were referred to the time intervals in minutes from the beginning of the meal. AUCs were calculated according to the trapezoidal model. Serum glucose was measured by enzymatic colorimetric assay; serum insulin was determined by immunoradiometric assay. | From the beginning of the meal for 180-min | 
| Variation in Morning Triglyceride and Free Fatty Acid (FFA) Area-Under the Curve (AUC)s After the Consumption of a Meal at 8:00 am Compared With Evening Glucose and Insulin AUCs After the Consumption of the Same Meal at 8:00 pm | Triglycerides and FFA values measured every 30 minutes after meal for 180-min. Time 0 was before the meal. Times 30, 60, 90, 120, 150 and 180 were referred to the time intervals in minutes from the beginning of the meal. AUCs were calculated according to the trapezoidal model. FFA concentrations were measured by a fluorometric assay. Plasma triglycerides were assayed by enzymatic colorimetric method. Serum glucose was measured by enzymatic colorimetric assay; serum insulin was determined by immunoradiometric assay. | From the beginning of the meal for 180-min | 
| Intra-individual Variations in the Values of Adrenalin and Noradrenalin, After the Morning and Evening Meal Consumption |  | Every 30-min from the beginning of the meal for 180-min | 
| Intra-individual Variations in the Values of Acylated Ghrelin After the Morning and Evening Meal Consumption |  | Every 30-min from the beginning of the meal for 180-min | 
| Intra-individual Variations in the Values of Glucagon-like Peptide-1 After the Morning and Evening Meal Consumption |  | Every 30-min from the beginning of the meal for 180-min | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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diet-induced thermogenesis, glucose, respiratory quotient