Influence of food intake on concentrations of plasma catecholamines and cortisol

Plasma concentrations of epinephrine, norepinephrine, dopamine and cortisol were determined in four healthy volunteers--resting completely in bed--before and after food intake. Meals were provided at 17.00 h on the first day and at 12.00 h on the second day of the test. Blood samples were drawn every 15 minutes. Epinephrine, norepinephrine, dopamine, and cortisol showed a clear dependence on food intake. After the meals plasma concentrations of the four analytes showed rises, which were more pronounced after lunch at 12.00 h than after dinner at 17.00 h. An increase of epinephrine was observed shortly before meal-times; this could be caused by physiological adaptation to the usual rhythm of food intake and reflex response to expectation of the meal.