"There's really no good that comes out of being overweight," said breast surgeon Dr. Deanna Attai.
Attai says excess fat may increase a woman's risk of getting breast cancer. Female hormones can fuel the growth of certain tumors.
"The estrogen and progesterone hormones are synthesized, or made, in the fat tissue. The enzyme that converts the precursors into the estrogen and progesterone are stored in the fat cells," Attai said. "So when you lose weight, your levels of these enzymes decrease, and so your hormone levels will decrease."
Fred Hutchinson Cancer researchers found that dropping as little as 5 to 10 percent of body weight may reduce a woman's breast cancer risk 25 to 50 percent. But it's not just about estrogen. Scientists believe lowering the body's inflammation levels may play a role because inflammation is also fueled by fat.
In the study, women who just dieted did not lower their risk as much as those who dieted and exercised, so experts say exercise is key.
"Women who have been treated for breast cancer and maintain an ideal body weight after treatment have a lower risk of developing a recurrence," Attai said.
But Attai notes that breast cancer is a very complex disease. While weight loss appears to reduce a woman's risk, that alone can't prevent breast cancer.
At the time 57-year-old Vickee Peterson was diagnosed with breast cancer five years, she was exercising regularly, but she also had a lot of stress working in television. Since her recovery, Peterson slowed down her hectic lifestyle and believes reducing your risk of cancer also includes cutting out stress.
Another thing you can do to reduce your risk of breast cancer is to quit smoking if you do smoke, and only drink moderate amounts of alcohol, which is no more than about a glass of wine a day.