Epidemiological and molecular genetics in human obesity

Obesity is a common and major human pathology with numerous and severe comp lications. It is a more and more sensitive public health problem. The epide miological approach aims at studying the pathology at the population level. Nowadays, all over the world, there are about 250 millions of obese people (with a BMI up to 30 kg/m(2)). In France, obesity concerns from 7 to 10 pe rcent of the adult population of the two teres. Epidemiological studies can also lead to formulate hypothesis on the pathophysiology and the genetics of obesity. Analysis of heritability, segregation and genotype-environment interactions allow to precise the genetic contribution in the occurrence of human obesity. Over the last years, we have noted progress in the field of molecular genetics of obesity owing to the elaboration of animal models, t he use of the quantitative trait loci (QTL), association studies, polymorph isms and candidate genes analysis. Despite the fact that there are now some genes with major effect on obesity, on the map of the human genome, the nu mber of loci and genes related to adiposity is dramatically increasing. So, obesity remains a model of complexity in multifactorial pathologies in hum an beings.