MONDAY July 7, 2008 (foodconsumer.org) -- Overweight women may be more likely to be diagnosed with advanced breast cancer, according to a new study presented at the Population Health 2008 Conference in Brisbane.

For the study, University of Melbourne researcher Dr Anne Cust and colleagues followed more than 60,000 Swedish women for more than 20 years from 1985 through 2005.

When entering the study, all participants were free of cancer and their blood levels of glucose, insulin and other hormones associated with obesity and diabetes risk.

Insulin resistance is commonly associated with overweight and physically inactivity and is often a precursor to Type 2 diabetes.

Dr Cust and colleagues found a strong link between being overweight and increased breast cancer risk in post-menopausal women.

"Women with insulin resistance or who were overweight were less likely to be diagnosed with stage 1 breast cancers but at greater risk of being diagnosed with stage 2 to 4 tumors – larger more advanced cancers,'' she said.

"We know that being overweight and having insulin resistance is a risk factor for getting cancer but - in the case of breast cancer - our study indicates that the cancer will be more advanced."

Dr. Cust's research was also recently published in the journal Breast Cancer Research and Treatment.

Overweight is very common in the West and it is believed that the increased prevalence is associated with the Western diet full of sugar, processed food and high intake of animal-based foods.

Two-thirds of non-institutionized adults age 20 years and over in the United States are overweight according to the Centers for Disease Control and Prevention.

Breast cancer hits182,500 women and kills 45,000 each year in the U.S. according to the National Cancer Institute.