ORIGINAL ARTICLE Higher body fat percentage is associated with increased cortisol reactivity and impaired cognitive resilience in response to acute emotional stress LR Mujica-Parodi 1,2 , R Renelique 1,2 and MK Taylor 3 1 Laboratory for the Study of Emotion and Cognition, Department of Biomedical Engineering, Stony Brook University School of Medicine, Stony Brook, NY, USA; 2 Laboratory for the Study of Emotion and Cognition, Department of Psychiatry, Stony Brook University School of Medicine, Stony Brook, NY, USA and 3 Stress Physiology Research Core, Department 162, Warfighter Performance, Naval Health Research Center, San Diego, CA, USA Objective: Cortisol is elevated in individuals with both increased emotional stress and higher percentages of body fat. Cortisol is also known to affect cognitive performance, particularly spatial processing and working memory. We hypothesized that increased body fat might therefore be associated with decreased performance on a spatial processing task, in response to an acute real-world stressor. Design: We tested two separate samples of participants undergoing their first (tandem) skydive. In the first sample (N ¼ 78), participants were tested for salivary cortisol and state anxiety (Spielberger State Anxiety Scale) during the plane’s 15-min ascent to altitude in immediate anticipation of the jump. In a second sample (N ¼ 20), participants were tested for salivary cortisol, as well as cardiac variables (heart rate, autonomic regulation through heart rate variability) and performance on a cognitive task of spatial processing, selective attention and working memory. Results: In response to the skydive, individuals with greater body fat percentages showed significantly increased reactivity for both cortisol (on both samples) and cognition, including decreased accuracy of our task of spatial processing, selective attention and working memory. These cognitive effects were restricted to the stress response and were not found under baseline conditions. There were no body fat interactions with cardiac changes in response to the stressor, suggesting that the cognitive effects were specifically hormone mediated rather than secondary to general activation of the autonomic nervous system. Conclusions: Our results indicate that, under real-world stress, increased body fat may be associated with endocrine stress vulnerability, with consequences for deleterious cognitive performance. International Journal of Obesity (2009) 33, 157–165; doi:10.1038/ijo.2008.218; published online 18 November 2008 Keywords: body fat; cortisol; emotional stress; cognition; body mass index; spatial processing Introduction Cortisol, known generally as the ‘stress hormone,’ is an important endocrine output of the body’s hypothalamic– pituitary–adrenal axis response to emotional and physical stress. The impact of stress on cognitive performance appears to be primarily mediated through cortisol, due to cortisol’s effects on the hippocampus 1,2 and prefrontal cortex. 3 These effects are particularly associated with executive and spatial processing, as well as working memory, and have been repeatedly demonstrated both when cortisol is introduced exogenously 4,5 and when it is endogenously secreted during emotionally or physically stressful events. 6–11 Cortisol and visceral body fat are known to have a strong influence upon one another. Unlike peripheral fat, visceral fat allows for much greater blood flow, contains increased glucocorticoid receptors and therefore is sensitive to the fat-accumulating deposits of cortisol and triglycerides. Visceral adipose tissue becomes larger when it encounters cortisol, 12 excessive secretion of cortisol at baseline increases the accumulation of central fat deposits 13,14 and central fat deposits are significantly larger in individuals with diseases that cause cortisol dysregulation, such as Cushing’s syndrome 15 and severe depression. 16–19 Received 30 May 2008; revised 29 September 2008; accepted 6 October 2008; published online 18 November 2008 Correspondence: Professor LR Mujica-Parodi, Laboratory for the Study of Emotion and Cognition, Department of Biomedical Engineering, Stony Brook University School of Medicine, Health Sciences Center T18, Stony Brook, NY 11794-8181, USA. E-mail: lmujicaparodi@gmail.com International Journal of Obesity (2009) 33, 157–165 & 2009 Macmillan Publishers Limited All rights reserved 0307-0565/09 $32.00 www.nature.com/ijo