[What do we know about obesity?].

The prevalence of obesity is increasing rapidly in most industrialized countries and it is known that obesity is associated with increased risk of cardiovascular morbidity and mortality. Commonly, obesity is defined by the Body Mass Index (BMI). However, BMI fails to consider body fat distribution. The relationship between the risk of metabolic-cardiovascular diseases and body fat distribution indices, rather than measures of the degree of body fatness as expressed by BMI, has long been recognized. Clinical and epidemiological research has found waist circumference to be the best anthropometric indicator of both total body fat and intra-abdominal fat mass. Android obesity is associated with metabolic syndrome and increased cardiovascular risk through molecular mechanisms possibly linking the metabolic syndrome to hemostatic and vascular abnormalities. Obesity guidelines suggest the need for weight reduction using behavioural change to reduce caloric intake and increasing physical activity. A realistic goal for weight reduction is to reduce body weight by 5% to 10% over a period of 6 to 12 months. Combined intervention of a low calories diet, increased physical activity, and behaviour therapy provides better outcomes for long-term weight reduction and weight maintenance than programs that use only one or two of these modalities. The anorexiant drugs affect neurotransmitters in the brain. The sibutramine has norepinephrine and serotonin effects. Orlistat has a different mechanism of action: the reduction of fat absorption. Recently, the blockade of the endocannabinoid system with rimonabant may be a promising new strategy.