A recent study called The Strong Heart study (SHS) concluded that obesity causes heart enlargement and impaired heart pumping function in adolescence. The study included 460 American Indian teens, whose hearts were examined to measure size, shape and pumping function. Those who were overweight or obese had larger and heavier hearts, thought not to be totally related to changes in blood pressure that can occur with obesity. Those teens that were obese also had signs of abnormal pumping function.

While this study was confined to the American Indian population, other studies of different ethnic groups, including Caucasians and African Americans, have demonstrated similar results.