Researchers at Harvard University and the National Institute of Health examined clinical data from more than 44,000 women that were followed over 16 years.
During that time, 3,507 of the women died --1,748 of cancer and 751 of heart disease.
Women with waist size equal to or greater than 35 inches were about twice as likely to die of heart disease and cancer when compared to women with a waist size less than 28 inches, regardless of their body mass index.
The findings were published in the journal Circulation.
"Although maintaining a healthy weight should continue to be a corner stone in the prevention of chronic diseases and premature death, maintaining a healthy waist size should also be an important goal," the study authors wrote.
