A new report in the "Journal of American College of Cardiology" says the procedure seems to help overly stressed hearts return to more normal function and structure.
Doctors followed over 400 severely overweight people who had gastric bypass surgery and compared them with a group that did not undergo the procedure.
Two years after the operation, ultrasounds in the gastric bypass patients showed a "remodeling" of heart structure.
That indicated the hearts were less stressed and had returned to a more normal size.
Researchers say obese individuals often have signs of structural changes in their hearts.