Horm Metab Res 2009; 41(4): 261-270
DOI: 10.1055/s-0028-1119377

© Georg Thieme Verlag KG Stuttgart · New York

The Contribution of Psychosocial Stress to the Obesity Epidemic: An Evolutionary Approach

M. Siervo 1 , J. C. K. Wells 2 , G. Cizza 3
  • 1Addenbrooke's Hospital, Cambridge, UK
  • 2Childhood Nutrition Research Centre Institute of Child Health, London WC1N 1EH, UK
  • 3Clinical Endocrinology Branch, NIDDK, National Institute of Health (NIH), Bethesda, Maryland, USA
Further Information

Publication History

received 02.06.2008

accepted 15.10.2008

Publication Date:
20 January 2009 (online)


The Thrifty Gene hypothesis theorizes that during evolution a set of genes has been selected to ensure survival in environments with limited food supply and marked seasonality. Contemporary environments have predictable and unlimited food availability, an attenuated seasonality due to artificial lighting, indoor heating during the winter and air conditioning during the summer, and promote sedentariness and overeating. In this setting the thrifty genes are constantly activated to enhance energy storage. Psychosocial stress and sleep deprivation are other features of modern societies. Stress-induced hypercortisolemia in the setting of unlimited food supply promotes adiposity. Modern man is becoming obese because these ancient mechanisms are efficiently promoting a positive energy balance. We propose that in today's plentifully provisioned societies, where sedentariness and mental stress have become typical traits, chronic activation of the neuroendocrine systems may contribute to the increased prevalence of obesity. We suggest that some of the yet unidentified thrifty genes may be linked to highly conserved energy sensing mechanisms (AMP kinase, mTOR kinase). These hypotheses are testable. Rural societies that are becoming rapidly industrialized and are witnessing a dramatic increase in obesity may provide a historical opportunity to conduct epidemiological studies of the thrifty genotype. In experimental settings, the effects of various forms of psychosocial stress in increasing metabolic efficiency and gene expression can be further tested.



G. Cizza

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