Healthy
Conditions
Keywords
glycemic index, inactivity, insulin sensitivity, metabolic flexibility, arterial stiffness, young men
Brief summary
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
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).
Interventions
DIETARY_SUPPLEMENTsoft drinks
soft drinks with palatinose and maltodextrin
Sponsors
University of Hohenheim
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
SINGLE (Subject)
Eligibility
Sex/Gender
MALE
Age
18 Years to 35 Years
Healthy volunteers
Yes
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
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Influence of GI on inactivity-induced changes in insulin sensitivity as measured by an OGTT | 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 | 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 |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Influence of GI on inactivity-induced changes in metabolic flexibility as measured by indirect calorimetry (RER, respiratory exchange ratio) | 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 | 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) |
Other
| Measure | Time frame | Description |
|---|---|---|
| Influence of GI on inactivity-induced changes in parameters of arterial stiffness as measured by pulse wave velocity | 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 | impact of GI on inactivity-induced changes (difference between the end of high activity and low activity phases) in arterial stiffness (as assessed by pulse wave velocity) |
Countries
Germany
Outcome results
None listed