2.2. Experimental Protocol
±, rice or pasta dressed
In a randomized, cross-over study, the subjects received mixed standardized meals of different compositions on two different days spaced apart by a washout period of 7 days. The meals were consumed at 9 o’clock in the morning after having fasted for at least 12 h. Each meal satisfied ~40% of an individual’s total energy requirement, estimated by multiplying predicted resting energy expenditure [Mediterranean meal: consisted of a sandwich of white bread, ham, oil, and tomato. Of the energy provided (39.1 ± 1.3% of TEE), 55.4 ± 1.1% was derived from carbohydrates (136.4 ± 16.3 g), 27.0 ± 0.8% from lipids, and 17.6 ± 1.0% from protein; the content of dietary fiber was 7.1 ± 1.0 g (7.4 ± 0.3 g/1000 kcal).Ketogenic meal: consisted of mascarpone cheese, hazelnuts, and cocoa powder with a ketogenic ratio (the ratio of the fat amount in grams to the combined protein and carbohydrate amount in grams) of 4:1 (mean 3.95, range 3.78–4.08).As previously described [The evening before each experiment, the subjects were asked to consume a standardized dinner consisting of rice or pasta dressed with oil and/or Parmesan cheese and/or tomato sauce, meat or fish, vegetables seasoned with olive oil, bread, and fresh fruit. Water was the only beverage allowed.On the day of the test, the subjects arrived at the laboratory at 8 o’clock in the morning: they were seated in a comfortable room and intravenous catheters were placed into an antecubital vein. Venous blood samples were obtained at baseline and at 10, 20, 30, 45, 60, 90, 120, and 180 min after test meal consumption in order to assess plasma glucose, insulin, and 