Experts say that obesity is a disease that now affects nearly one-third of the adult American population, approximately 60 million people, and the latest study on the condition suggests that health risks to women who are obese may have been underestimated.

This study has found that the more obese a woman is, the greater her risk for coronary heart disease, hypertension, diabetes, high blood pressure and death.

Researchers at the University of Pittsburgh conducted a study based on information gathered over a seven year period on weight, death, and cardiovascular disease among more than 90,000 ethnically-diverse U.S. women.

Obesity falls into three categories and is based on body mass index (BMI); obesity 1 equates to a BMI of 30 to 34.9; obesity 2 to a BMI of 35 to 39.9; and obesity 3 to a BMI of 40 or more.

The last two categories are often called severe obesity and are becoming increasingly common in the U.S. and by the year 2000, two percent of all U.S. women were considered severely obese.

The researchers found that the higher a woman’s level of obesity, the greater her health risks and the greater the impact on her life expectancy.

The research supports research and publications by the American Obesity Association which also says obesity plays a significant role in causing poor health in women, and negatively affects the quality and length of life.

Obesity appears to be more common in low-income women in minority groups and middle-age women are at a particularly high risk.

There are apparently many obesity-related conditions, which uniquely or mostly affect women, including arthritis, osteoarthritis, birth defects, breast cancer, endometrial cancer, cardiovascular disease, gallbladder disease, infertility and obstetric and gynecological complications, and urinary stress incontinence.

The association says that a direct association has been found between body weight and deaths from all-causes in women, ages 30 to 55 and when BMI exceeds 30, the relative risk of death related to obesity increases by 50 percent.