Nutritional support of obese critically ill patients.

Obesity is a common medical condition affecting more than 1 in 10 adults in Western European countries [1]. Its prevalence varies considerably in different countries. In Europe, it amounts to about 10–15% of the middleaged population. It is highest in Eastern European countries, in North America, high in Africa and Eastern Asian countries, where it is strongly associated with poverty, but lower in Japan and China. There has been a progressive rise in the overall prevalence of obesity during the last decade, both in adults and children. The medical and economical consequences are enormous. The medical spectrum of obesity is wide, ranging from simple overweight without associated medical risk, to morbid obesity with severe associated comorbidities [1]. Various diagnostic criteria have been used; the most useful and simplest relies on the body mass index (BMI) scale. According to the International Obesity Task Force of the Word Health Organization, the severity of obesity is classified into 3 main categories: (1) overweight: BMI 25–30; (2) obesity: BMI 30–40, and (3) morbid obesity: BMI over 40 kg/m2. In addition to the absolute amount of body fat, as reflected by the BMI, body fat distribution is important: centralization of body fat to the abdominal visceral stores is associated with the development of systemic and metabolic complications [2]. Body fat distribution can easily be assessed in clinical practice using simple anthropometric measurements, such as waist circumference: a circumference over 102 cm in European men and 88 cm in women is an independent risk factor for a cluster of medical and metabolic