Healthy Subjects
Conditions
Keywords
gluconeogenesis, de novo lipogenesis, intramyocellular lipids, muscle glycogen, fructose
Brief summary
A high fructose diet increases fasting and post-prandial triglyceride (TG) concentrations in sedentary healthy human subjects.These effects may be secondary to fructose-induced hepatic de novo lipogenesis. Recent evidence indicate that exercise can prevent fructose induced dyslipidemia.This study will evaluate 1. how exercise effects the metabolic fate of oral fructose 1a) when exercise is performed before fructose ingestion 1b) when exercise is performed after fructose ingestion Metabolic effects of exercise will be assessed in healthy male subjects by measuring fructose oxidation (13CO2 production), fructose conversion into glucose (13C glucose concentrations in blood) and hepatic fructose conversion into lipid (13C palmitate-very low density lipoprotein (VLDL) concentrations in blood) after ingestion of 13C-labelled fructose meals 2. how fructose and protein modulate muscle glycogen and intramyocellular lipid repletion after exercise Healthy male subjects will be fed various fructose, glucose, lipid and whey protein meals after a glycogen/intramyocellular lipid depleting exercise. The effects of meals' composition will be assessed after 24 hours by measuring intramyocellular lipids and glycogen using proton-magnetic resonance spectroscopy (MRS).
Interventions
OTHERexercise
cycling at 100W during 60 min
DIETARY_SUPPLEMENTfructose
isocaloric nutrition with fructose, cream and whey protein during the 24 hour following a glycogen/intramyocellular lipid depleting exercise
DIETARY_SUPPLEMENTglucose
isocaloric nutrition with glucose, cream and whey protein during the 24 hour following a glycogen/intramyocellular lipid depleting exercise
Sponsors
University of Bern
Centre Hospitalier Universitaire Vaudois
University of Lausanne
Study design
Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
BASIC_SCIENCE
Masking
NONE
Eligibility
Sex/Gender
MALE
Age
18 Years to 40 Years
Healthy volunteers
Yes
Inclusion criteria
* males * 18-40 years old * 19 kg/m2\>BMI\>25kg/m2 * moderate to high usual physical activity * non-smokers
Exclusion criteria
* family history of diabetes mellitus * ECG anomaly * any medication * participation to blood spending or other clinical study in the 3 months before the beginning of this study * consumption of drugs * consumption of more than 50g alcool/week * family history of food intolerance
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Plasma triglyceride | measurements in fasting conditions and every hour from 7:00 am to 4:00 pm (up to 9 hours) | measurement of total and VLDL-TG concentrations in study 1 |
| intramyocellular lipids | after glycogen/intramyocellular lipid depleting exercise and after 24 hour controlled feeding post exercise | Measurement by 1H-MRS in muscle vastus lateralis in study 2 |
| Fructose conversion into lipids | measured from 7:00 am to 4:00 pm in study 1 (up to 9 hours) | Estimated from 13C palmitate-VLDL concentration |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Fructose conversion into glucose | measured between 7:00 am and 4:oo pm (up to 9 hours) | measurements obtained from plasma 13C glucose concentrations and whole body glucose production measured by 6,6 d2 glucose in study 1) |
| exogenous lipid oxidation | measured from 7:00 am to 4:00 pm in study 2 (up to 9 hours) | Lipids ingested will be labeled with 13C-triolein, and exogenous lipid oxidation will be measured from breath 13CO2 production |
| intramyocellular glycogen concentrations | after glycogen/intramyocellular lipid depleting exercise and after 24 hour controlled feeding post exercise | Measured by 1H-MRS in muscle vastus lateralis in study 2 |
| fructose oxidation | measured from 7:00 am to 4:00 pm in study 1 (up to 9 hours) | Calculated from breath 13CO2 production |
Countries
Switzerland
Outcome results
None listed