Obesity paradox or inappropriate study designs? Time for life-course epidemiology

Obesity is a major risk factor for cardiovascular disease (CVD) and all-cause mortality [1]. On the basis of individuals’ level of BMI, this relationship is characterized by a J-shape with the nadir – that is, the point of the highest survival rate – around 22.5–25 kg/m2. Paradoxically, among patients with established CVD, this relationship seems to change in such a way that the nadir shifts to the right, with levels of BMI belonging to the...