Joint association of physical activity and body mass index with cardiovascular risk: a nationwide population-based cross-sectional study

The prevalence of overweight and obesity has reached pandemic proportions, and people with these conditions present with an increased cardiometabolic risk.1 Some evidence suggests, however, that a high cardiorespiratory fitness (CRF) might mitigate the detrimental effects of excess body weight on cardiometabolic health, termed the ‘fat but fit’ paradox.2 For instance, a recent meta-analysis concluded that although both overweight/obesity and a low CRF can increase the risk of mortality from cardiovascular diseases (CVD), low CRF is actually a stronger predictor.3 Thus, it has been proposed that health policies should focus on physical activity (PA)-based interventions aimed at improving CRF rather than—or at least as much as—on weight loss strategies,3 although some controversy remains.2 To clarify the existence of the ‘fat but fit’ [or ‘elevated body mass index (BMI) but active’] paradox, in this observational study, we assessed the joint association between different BMI categories and...