Background:The sharp increase of plasmatic and salivary cortisol that follows awakening is called cortisol awakening response (CAR). CAR alterations are proposed as indicator of
stress. The saliva collection protocol for CAR determination demands that individuals must remain fasted during the first hour after awakening, period in which saliva samples are collected. This
contributes to the low adherence to the protocol, jeopardizing the results. The aim of this study is to verify if food intake during this period or the composition of this meal changes the CAR.
Methods: Method: Sixteen male (17.31 ± 0.27 year-old) basketball players participated in this study. Breakfast compositions have been defined so that on each day one type of
macronutrient prevailed, and in one day the meal composition was balanced. Saliva samples were collected immediately, 30 and 60 min after waking up, maintaining the individual fasted during the entire
period or allowing the intake of a meal after the first sample collection. Data were compared by two-way ANOVA followed by Bonferroni test. Differences were considered significant when p < 0.05.
Results:The saliva cortisol concentration immediately after awakening did not significantly differ between the days of saliva collection (8.48 ± 2.09; 10.41 ± 1.24; 7.94 ± 1.44; 12.44
± 2.38; 7.67 ± 1.23 nM). The CAR was significantly higher (p= 0.001) after intake of the meal with predominance of lipids (29.22 ± 4.66 nM) than when subjects fasted (16.01 ± 3.18nM) or had a
breakfast with predominance of carbohydrate (13.44 ± 1.58) or protein (10.78 ± 2.04 nM).
Conclusions: Conclusion: It is concluded that a breakfast rich in lipids alters the CAR, but meals with bal-anced composition or rich in carbohydrates or proteins do
not alter this response, and therefore they can be taken in the period of saliva collection for CAR determination. Financial support: CAPES.