title: Chewing after stress: psychosocial stress influences chewing frequency, chewing efficacy, and appetite.
abstract: 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 frequency, 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, η(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.
  
  
  CONCLUSIONS
  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.
authors.affiliation: Institute of Psychotherapy and Psychosomatic Medicine, School of Medicine, Technische Universität Dresden, Germany. Electronic address: katja.petrowski@mailbox.tu-dresden.de.
authors.forename: Katja
authors.initials: K
authors.lastname: Petrowski
authors.affiliation: Institute of Psychotherapy and Psychosomatic Medicine, School of Medicine, Technische Universität Dresden, Germany.
authors.forename: Gloria-Beatrice
authors.initials: GB
authors.lastname: Wintermann
authors.affiliation: Institute of Psychotherapy and Psychosomatic Medicine, School of Medicine, Technische Universität Dresden, Germany.
authors.forename: Peter
authors.initials: P
authors.lastname: Joraschky
authors.affiliation: Institute of Semiconductors and Microsystems, Technische Universität Dresden, Germany; Fraunhofer Institute for Photonic Microsystems (IPMS), Dresden, Germany.
authors.forename: Sebastian
authors.initials: S
authors.lastname: Päßler
mesh_terms: D000293:Adolescent; D000328:Adult; D000368:Aged; D001066:Appetite / Q000502:physiology*; D004435:Eating / Q000523:psychology; D005260:Female; D006801:Humans; D006854:Hydrocortisone / Q000378:metabolism; D008297:Male; D008409:Mastication / Q000502:physiology*; D008875:Middle Aged; D010507:Periodicity; D012463:Saliva / Q000378:metabolism; D013315:Stress, Psychological / Q000503:physiopathology / Q000523:psychology; D055815:Young Adult
chemical_list: D006854:Hydrocortisone
keywords: Appetite; Chewing frequency; Cortisol; Eating preference; Hypothalamic-pituitary-adrenocortical axis