The results validated the link between obesity and cancer.
"Heavier women are exposed to more estrogen and we looked across our ethnic groups and found all of them had an increased risk of breast cancer," said Wilkens.
The risk was 20 percent, but the study also found that in Hawaiians and Japanese that risk jumped to 50 percent.
Wilkens said the risk increased for other diseases like diabetes too.
The findings were just published this year.
"You want to keep a healthy lifestyle, whether that means increasing physical activity, maintaining a healthy body weight and make sure you are getting preventative screenings," said White. "There are things people can do to keep a healthy lifestyle and that's the message we want to carry forward."
Two decades of research hoping to save lives.