According to the Centers for Disease Control and Prevention, obesity results when human body fat accumulates over time, mainly due to what is called a chronic energy imbalance—in other words, that calories consumed exceed calories expended in such activities as exercise. It is now known that, as of this writing, obesity is a major health hazard worldwide; in fact, in the United States alone, it is estimated that around 27 percent of adults are obese. Obesity is also costly, as it is associated with workplace absenteeism as a result of such obesity-related diseases as diabetes, hypertension, heart disease, and some cancers.