Biology and You

You and Your Genes

What is obesity?

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.


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