The American Cancer Society wants to set the record straight.

One of the largest medical studies ever undertaken has confirmed what many public health officials already knew and feared, but something the general U.S. populations doesn’t recognize: Being overweight can give you cancer.

The message was sent loud and clear back in August during the American Cancer Society’s Great American Eat Right Challenge: excess body fat is an important cause of cancer.

The recent Million Women Study in the United Kingdom found that overweight and obese women are at higher risk of developing and dying of cancer.

Specifically, the study found that excess weight causes cancers of the esophagus, endometrium (uterine lining), ovary, kidney and pancreas, as well as leukemia, multiple myeloma and non-Hodgkin's lymphoma.

It also causes breast cancer - but only in post-menopausal women.

Another study released at the same time appeared to contradict some of the Million Women findings.

A report from the Centers for Disease Control and Prevention, published in the Journal of the American Medical Association, said being overweight - but not obese - does not appear to raise your risk of dying from cancer.

But Dr. Michael Thun of the American Cancer Society said the Million Women Study "has more statistical power and is able to look at a greater array of cancers with more precise estimates of risk."

But he noted that the conclusions of the two studies were more similar than different.

Both found that obese individuals had an increased risk of death from certain cancers, including breast, ovary and endometrium.

Both the CDC study and Million Women defined overweight as having a body mass index between 25 and 29.9.

Someone with a BMI of 30 or more was considered obese.