Subjects arrived at the laboratory after a 12-hour
overnight fast. They lay in a supine position for 10 minutes
before continuous measurement of pulmonary gas exchange
for a 25-minute period using a ventilated hood (Oxycon Pro;
Jaeger, Hoechberg, Germany) to allow assessment of
metabolic rate and rate of fat and carbohydrate oxidation
via indirect calorimetry [25]. A cannula (Vasofix; Braun,
Melsungen, Germany) was inserted into an antecubital vein,
and the baseline blood sample was taken 10 minutes after
cannulation. Subjects subsequently underwent an oral
glucose tolerance test (OGTT). Briefly, they consumed a
drink containing 75 g of anhydrous glucose in 300 mL of
water; and blood samples were taken at 30-minute intervals.