Psychoneuroendocrinology (2014) 48, 64—76 Available online at www.sciencedirect.com ScienceDirect jou rn al h om epage: www.elsevier.com/locate/psyneuen Chewing after stress: Psychosocial stress influences chewing frequency, chewing efficacy, and appetite Katja Petrowski a,* , Gloria-Beatrice Wintermann a , Peter Joraschky a , Sebastian Päßler b,c a Institute of Psychotherapy and Psychosomatic Medicine, School of Medicine, Technische Universität Dresden, Germany b Institute of Semiconductors and Microsystems, Technische Universität Dresden, Germany c Fraunhofer Institute for Photonic Microsystems (IPMS), Dresden, Germany Received 27 May 2013; received in revised form 11 June 2014; accepted 11 June 2014 KEYWORDS Hypothalamic- pituitary- adrenocortical axis; Cortisol; Chewing frequency; Eating preference; Appetite Summary Background: Psychosocial stress is accompanied by an increase in the activity of the hypothalamic-pituitary-adrenocortical (HPA)-axis and by an increase in food intake. At present, no studies have been conducted to examine the impact of a potent laboratory stress test on the chewing frequency. Methods: Thirty-one healthy participants (14 females, mean age 27.13) were compared after they had fulfilled the protocol of a standardized psychosocial stress test, the Trier Social Stress Test (TSST), and after a resting condition of silent reading in reference to their chewing fre- quency, chewing efficacy, food intake, and eating preferences. As part of the design free salivary cortisol levels and heart rate variability were measured repeatedly before and after the TSST and the resting condition. Results: After the TSST, the participants exhibited a significantly higher mean chewing frequency than after the resting condition (F(2,60) = 3.600, p = .035,  2 = .107). The testing condition had no influence on the amount of food intake. Following the psychosocial stress, however, the participants reported a significantly less general appetite (Z = -3.921, p < .001) and less of an appetite for eggs (Z = -2.023, p = .043) than after their resting condition. No correlation was found between the salivary cortisol response and the chewing frequency. Conclusion: The results indicated that psychosocial stress is associated with an increase in chewing frequency, as measured with a sound-based apparatus, and with a decrease in appetite. © 2014 Elsevier Ltd. All rights reserved. ∗ Corresponding author at: Institute of Psychotherapy and Psychosomatic Medicine, School of Medicine, Technische Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany. Tel.: +49 351 4583634; fax: +49 351 2636268. E-mail address: katja.petrowski@mailbox.tu-dresden.de (K. Petrowski). http://dx.doi.org/10.1016/j.psyneuen.2014.06.008 0306-4530/© 2014 Elsevier Ltd. All rights reserved.