title: Role of spontaneous physical activity in prediction of susceptibility to activity based anorexia in male and female rats.
abstract: Anorexia nervosa (AN) is a chronic eating disorder affecting females and males, defined by body weight loss, higher physical activity levels and restricted food intake. Currently, the commonalities and differences between genders in etiology of AN are not well understood. Animal models of AN, such as activity-based anorexia (ABA), can be helpful in identifying factors determining individual susceptibility to AN. In ABA, rodents are given an access to a running wheel while food restricted, resulting in paradoxical increased physical activity levels and weight loss. Recent studies suggest that different behavioral traits, including voluntary exercise, can predict individual weight loss in ABA. A higher inherent drive for movement may promote development and severity of AN, but this hypothesis remains untested. In rodents and humans, drive for movement is defined as spontaneous physical activity (SPA), which is time spent in low-intensity, non-volitional movements. In this paper, we show that a profile of body weight history and behavioral traits, including SPA, can predict individual weight loss caused by ABA in male and female rats with high accuracy. Analysis of the influence of SPA on ABA susceptibility in males and females rats suggests that either high or low levels of SPA increase the probability of high weight loss in ABA, but with larger effects in males compared to females. These results suggest that the same behavioral profile can identify individuals at-risk of AN for both male and female populations and that SPA has predictive value for susceptibility to AN.
authors.affiliation: Center for Integrative Medicine and Innovative Science, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile; Escuela de Nutricion, Facultad de Medicina, Universidad Andres Bello, Santiago, Chile. Electronic address: claudio.perez@unab.cl.
authors.forename: Claudio E
authors.initials: CE
authors.lastname: Perez-Leighton
authors.affiliation: Minneapolis VA Health Care System, Minneapolis, MN USA.
authors.forename: Martha
authors.initials: M
authors.lastname: Grace
authors.affiliation: Minneapolis VA Health Care System, Minneapolis, MN USA; Minnesota Obesity Center, University of Minnesota, Minneapolis, MN, USA; Department of Medicine, University of Minnesota, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
authors.forename: Charles J
authors.initials: CJ
authors.lastname: Billington
authors.affiliation: Minneapolis VA Health Care System, Minneapolis, MN USA; Minnesota Obesity Center, University of Minnesota, Minneapolis, MN, USA; Department of Food Science and Nutrition, University of Minnesota, St. Paul, MN, USA.
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Kotz
mesh_terms: D000818:Animals; D000855:Anorexia / Q000503:physiopathology*; D004195:Disease Models, Animal; D004198:Disease Susceptibility; D005260:Female; D008297:Male; D009043:Motor Activity / Q000502:physiology*; D010805:Physical Conditioning, Animal / Q000502:physiology*; D051381:Rats; D012420:Running / Q000502:physiology; D015431:Weight Loss / Q000502:physiology*
keywords: ABA; Activity-based anorexia; Anorexia nervosa; Behavioral models; Individual susceptibility; Inter-individual variability; Physical activity; Predictive models; SPA; Spontaneous physical activity; Support vector machines