While some studies say that individuals with higher body mass indexes may have lower mortality rates under certain conditions—such as older age or existing health conditions—the consensus among health professionals is that obesity increases the risk of numerous diseases, including heart disease, diabetes, and certain cancers.
The American Heart Association, for instance, states that "obesity is a major risk factor for heart disease and stroke." Similarly, the Centers for Disease Control and Prevention (CDC) highlights that "obesity is linked to many preventable health problems."