Effects of Fructose/Glucose-rich Diet on Brown Fat in Healthy Subjects (GB7)

Each subject will follow 3 metabolic studies (A, B and C), each lasting 7.5h which includes a 3h acute cold exposure.

These studies will be almost identical: same perfusion of tracers, same number of Positron Emission Tomography (PET) acquisitions and same number of Magnetic Resonance Imaging (MRI) associated with Magnetic Resonance Spectroscopy (MRS) acquisitions .

The difference will be in the diet ingested by the subjects two weeks before each metabolic study: during protocol A, the subjects will follow an isocaloric diet; during protocol B, the subjects will follow the same isocaloric diet supplemented with a daily beverage containing +25% of energy intake from fructose; and during protocol C, the subjects will follow the same isocaloric diet supplemented with a daily beverage containing +25% of energy intake from glucose.

Stool samples will be collected for each metabolic study for microbiome flora and metabolites.

Inclusion criteria

• Healthy subjects: subjects with normal glucose tolerance determined according to an oral glucose tolerance test and with a BMI < 27 kg/m2 without first degree of familial history of type 2 diabetes (parents, siblings).

Exclusion criteria

• Plasma triglycerides > 5.0 mmol/L at fasting;
• More than 2 alcohol consumption per day;
• More than 1 cigarette per day;
• History of total cholesterol level > 7 mmol/L, of cardiovascular disease, hypertensive crisis;
• Treatment with fibrates, thiazolidinedione, insulin, beta-blockers or other drugs with effects on insulin resistance or lipid metabolism (exception for anti-hypertensive drugs, statins or metformin);
• Presence of a non-controlled thyroid disease, renal or hepatic disease, history of pancreatitis, bleeding diatheses, cardiovascular disease or any other serious medical conditions;
• History of serious gastrointestinal disorders (malabsorption, peptic ulcer, gastroesophageal reflux having required a surgery, etc.);
• Presence of a pacemaker;
• Have undergone of PET study or CT scan in the past year;
• Chronic administration of any medication;