Influence of Daylong Glycemia on Detraining Induced Metabolic Changes

Study Overview
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Brief Summary
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Aim of the study is to investigate the impact of glycemic index (provided as soft drinks) on changes in insulin sensitivity, metabolic flexibility, and arterial stiffness in response to detraining. The investigators hypothesize that low glycemic soft drinks decrease the detraining-induced impairment of insulin sensitivity, metabolic flexibility and arterial stiffness.

Detailed Description
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The duration of the study is 7 weeks: two x 2 weeks intervention (phase A and phase B) with 3 weeks washout phase inbetween. Each 2-week intervention phase consists of an active week followed by an inactive week. in phase A subjects consume high GI (maltodextrin and sucrose) soft drinks during the inactive week. In phase B subjects consume a low GI soft drink (palatinose) during the inactive week. subjects were randomly assigned to either start with phase A or with phase B (cross over design). During the whole study duration all food is provided (55% CHO, 30% fat, 15% protein) Physical activity will be assessed by a step counter (active phase 7000-10000 steps/d and inactive phase 3000-4000 steps/d).

Official Title
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Einfluss Der Postprandialen Glykämie Auf Inaktivitäts-induzierte Veränderungen im Stoffwechsel

Conditions
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Healthy

Intervention / Treatment
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* Dietary Supplement: soft drinks


Participation Criteria
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Eligibility Criteria
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Inclusion Criteria: normal weight men, age 18-35 y, active life style, > 300 min sports/week Exclusion Criteria: food allergies, regular use of medication, smoking, chronic disease, vegan/vegetarian diet

Ages Eligible for Study
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Minimum Age: 18 Years
Maximum Age: 35 Years

Sexes Eligible for Study
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Male

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: Single


Arms and Interventions

| Participant Group/Arm | Intervention/Treatment |
| --- | --- |
| Experimental: low glycemic index<br>palatinose in soft drinks | Dietary Supplement: soft drinks<br>* soft drinks with palatinose and maltodextrin<br>|
| Experimental: high glycemic index<br>sucrose plus maltodextrin in soft drinks | Dietary Supplement: soft drinks<br>* soft drinks with palatinose and maltodextrin<br>|

What is the study measuring?
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Primary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Influence of GI on inactivity-induced changes in insulin sensitivity as measured by an OGTT | Influence of GI (glycemic index) on detraining-induced changes (difference between the end of high activity and low activity phases) in insulin sensitivity Insulin sensitivity is assessed by HOMA and Matsuda indices | the difference between the end of each 1 week activity phase (day 7 vs. day 14, low vs. high physical activity) is compared between high GI and low GI intervention | 

Secondary Outcome Measures

| Outcome Measure | Measure Description | Time Frame |
| --- | --- | --- |
| Influence of GI on inactivity-induced changes in metabolic flexibility as measured by indirect calorimetry (RER, respiratory exchange ratio) | Impact of GI on inactivity induced changes in metabolic flexibility Metabolic flexibility is defined as the body´s ability to adapt fuel oxidation to changing fuel availability and energy demand It is measured as change in fasting RER (fasting metabolic flexibility) and change in RQ (difference between the end of high activity and low activity phases) after an oral glucose tolerance test (postprandial metabolic flexibility) | the difference between the end of each 1 week activity phase (day 7 vs. day 14) is compared between high GI and low GI intervention | 

 Terms related to the study
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Keywords Provided by Centre Hospitalier Valida
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glycemic index, inactivity, insulin sensitivity, metabolic flexibility, arterial stiffness, young men