Obesity:The BIG issue
Authors: P. B. Persson and; A. Bondke Persson
Year: 2013

‘Alright, admitted: too little exercise. On the other hand, if I was to touch my toes, should they not have been placed a bit higher up?’ The probability is high that you are reading this ExActa seated in front of a computer screen. Having reached the postdoctoral level, life at the bench may to a large degree have been substituted by data analysis, manuscript preparation, project management and grant acquisition, that is, most of your day will be spent at the desk, sedentary. The ability to earn your money from an office instead of from physical labour has until recently been regarded as a status symbol, and is still so, depending on our geographic, cultural and socioeconomic environment. December has passed, especially in the north-western hemispheres being regarded as a month of indulgent eating and sitting inside rather than braving the cold. The last decades, however, have seen the rise of a global pandemic (Swinburn et al. 2011), which has become one leading cause of worldwide mortality, rooted largely in a lack of physical activity coupled with a season-independent surplus in nutrients: obesity. The phenomenon itself is not new: one of the most acclaimed Central European palaeolithic artefacts, demonstrating the outstanding craftsmanship of the artisan who lived and worked approx. 25 000 years ago, depicts a woman whom we would nowadays classify by visual diagnosis as at least severely, if not morbidly obese [Fig. 1]. The way she is portrayed, however, indicates that she was looked upon as a beauty rather than as suffering from a lifeshortening medical condition, as which obesity must clearly be regarded, given nowadays’ knowledge. This article looks at current research trends in understanding the pathophysiology, consequences and therapeutic strategies towards obesity. The WHO defines obesity as abnormal or excessive fat accumulation that presents a risk to health (World Health Organization 2012) and is classified by body mass index (BMI) [Fig. 2]. Genetic susceptibility is debated, but seems to play a subordinate role in contrast to diet and a sedentary lifestyle: although especially twin studies had shown that within the largely unvaried environments of industrialized countries genetic differences do account for BMI differences, percentage estimates vary widely (Yang et al. 2007), while the individual phenotypic expression ‘depends largely on environmental factors’ (Ravussin & Swinburn 1992). Obesity reduces life expectancy (Haslam & James 2005, Berrington de Gonzalez et al. 2010), particularly through its association with metabolic syndrome, cardiovascular disease and cancer (Bray et al. 2009, Poirier et al. 2006), significantly increasing morbidity from, for example, respiratory and musculoskeletal system diseases (Haslam & James 2005). The strongest causative link has been shown between obesity, insulin resistance and the development of type 2 diabetes mellitus (DM2) (Seidell 2000). Obesity induces a multitude of metabolic changes such as oxygen radical formation (Hey-Mogensen et al. 2012), which we are probably just beginning to understand. The chronic alterations of the mechanisms regulating food intake and body fat mass often make obesity refractory to treatment (Guyenet & Schwartz 2012). There is consensus among clinicians and researchers alike that only long-term lifestyle changes (diet and exercise) warrant success and provide a foundation for other therapeutic interventions. Medications aim at, for example, reducing lipid resorption (orlistat) or interfere with central appetite regulation systems