Being fat in middle age may slash a woman's chances of making it to her golden years in good health.

A new study shows fat, middle-aged women reduce their chances of living to 70 by almost 80 percent.

American researchers observed more than 17,000 female nurses with an average age of 50.

All the women were healthy when the study began in 1976.

Researchers monitored their weight, along with other health changes, every two years until the year 2000. 

A woman's chances of living past 70 dropped by five percent for every two pounds she gained after age 18, according to the study.

In a separate study, being overweight may become the leading cause of cancer in women in Western countries in the coming years.

That study shows that being fat accounts for up to eight percent of cancers in Europe.

Experts say that number will go up substantially as the obesity epidemic continues.

In Europe, colorectal cancer, breast cancer in menopausal women, and endometrial cancer accounted for 65 percent of all cancers linked to being fat.