title: Chew and Spit (CHSP): a systematic review.
abstract: BACKGROUND
  This systematic review is an evaluation of the empirical literature relating to the disordered eating behaviour Chew and Spit (CHSP). Current theories postulate that CHSP is a symptom exhibited by individuals with recurrent binge eating and Bulimia Nervosa.
  
  
  OBJECTIVE
  The review aimed to identify and critically assess studies that have examined the distribution of CHSP behaviour, its relationship to eating disorders, its physical and psychosocial consequences and treatment.
  
  
  METHODS
  A systematic database search with broad inclusion criteria, dated to January 2016 was conducted. Data were extracted by two authors and papers appraised for quality using a modified Downs and Black Quality Index.
  
  
  RESULTS
  Nine studies met the inclusion criteria. All were of clinical samples and majority (n = 7) were of low quality. The pathological action of chewing food but not swallowing was reported more often in those with restrictive type eating disorders, such as Anorexia Nervosa, than binge eating type disorders. CHSP also was reported to be an indicator of overall severity of an eating disorder and to appear more often in younger individuals. No studies of treatment were found.
  
  
  CONCLUSIONS
  Conclusions were limited due to the low quality and small numbers of studies based on clinical samples only. Further research is needed to address gaps in knowledge regarding the physiological, psychological, social, socioeconomic impact and treatment for those engaging in CHSP.
authors.affiliation: School of Medicine, University of Sydney, Sydney, Australia.
authors.forename: Phillip
authors.initials: P
authors.lastname: Aouad
authors.affiliation: Centre for Health Research, School of Medicine, Western Sydney University, Penrith, Australia.
authors.forename: Phillipa
authors.initials: P
authors.lastname: Hay
authors.affiliation: School of Medicine, University of Sydney, Sydney, Australia.
authors.forename: Nerissa
authors.initials: N
authors.lastname: Soh
authors.affiliation: School of Psychology, University of Sydney, Sydney, Australia.
authors.forename: Stephen
authors.initials: S
authors.lastname: Touyz
keywords: Abnormal eating; Anorexia; Bulimia; C/S; CHSP; Chew and Spit; Chewing and spitting; EDNOS; Eating disorder; Oral expulsion syndrome