In obese subjects, there is a "low grade" inflammatory state characterized by the moderate but chronic systemic rise of a panel of molecules (adipokines), which carry out, in addition to pro- or anti-inflammatory actions, several immune or metabolic functions, associated with a macrophagic infiltration in adipose tissue. These two factors provide a better understanding of the pathophysiology of obesity and its potential metabolic, cardiovascular or hepatic complications. A small or even moderate reduction of weight significantly reduces circulating inflammatory markers, modulates adipose tissue profile of inflammatory genes and the risks associated with obesity.