[Overweight. A valid predictor of cardiometabolic risk?]

A commonly held notion directly correlates overweight and obesity with cardiometabolic risk. A number of studies have recently questioned this belief. The classic measure of obesity, the body mass index, appears less valid to properly indicate increased fat mass and, in particular, potentially harmful changes in fat depots. Moreover, depot- and age-specific alterations including increases in fat mass are physiologic throughout life and may not be associated with an increased risk for diabetes or cardiovascular complications. In contrast, they may rather entail multi-system adaptations that are protective, e. g. to cardiovascular and bone health, and represent an explanation for what has recently been called "benign obesity". Endocrine as well as thermogenic functions of fat cells appear to be critical for the underlying biology. In this article, we highlight recent epidemiologic and biologic insights arguing against the assumption of overweight as a simple measure of disease. Finally, using selected clinical cases we demonstrate the ill-informed nature of an "overweight-focused" approach and delineate a practical algorithm to identify overweight patients at cardiometabolic risk.