The continued understanding of the role that health-related fitness plays in preventing chronic diseases such as type 2 diabetes is imperative. Two key components of health-related fitness are cardiovascular endurance (fitness) and body composition (fatness). Though the fit versus fat debate has received marked attention in recent years regarding the longevity of life, less is known regarding disease prevention. Fitter individuals tend to be less fat but this is not always the case, and conversely, leaner individuals are not always more fit. Therefore, a more nuanced understanding is needed regarding the interplay of fitness and fatness.
The results of some studies have indicated that fatness plays more of an important role in the onset of diabetes while other studies showed that fitness and fatness are comparable contributors. For this reason, fitness and fatness may better be represented in tandem. Therefore, a new approach for capturing relative degree of fitness and fatness is now under investigation termed the fit-fat index (FFI). This single index may provide a method whereby degree of change in fitness, fatness or both indicates a reduction in risk. In short, FFI may provide a better way of setting health-related fitness goals that improve self-efficacy and sustain behavior change towards disease prevention.