Causes of morbid aposity (BMI>40)
The development (pathogenesis) and cause (aetiology) of morbid obesity as an independent clinical condition involves several causal factors, and can only be understood if those factors are seen as a whole (see other chapters on "Adiposity"). The basis for it, even the milder forms, is surplus energy. This surplus is generally small (e.g. 2%) but in the long run (years to decades) may lead to a person becoming extremely overweight, even if interrupted by therapies, without the affected person even being conscious of his/her excessive eating.
Most patients have a dismal history with regard to their weight and increasingly suffer from secondary diseases. In epidemiological studies, well-examined socio-cultural and biological factors such as eating habits, "civilisation", motherhood, marital status, low education level or low income are not sufficient on their own to understand morbid obesity. The genetic component also seems to play a significant role in its manifestation.