The study found that the higher a woman's body mass index (BMI), the lower her chances were for survival.
Researchers also concluded that women who were lean at mid-life were the most likely to be in good mental and physical health after the age of 70.
A BMI between 19 and 25 is considered healthy, 25 to 30 is overweight and people with a BMI higher than 30 are considered medically /*obese*/.
The study accounted for mitigating factors including smoking and diet.
It is published in the medical journal BMJ.
The Associated Press contributed to this report.
- Link: Nurses' Health Study