A recent study published in the Journal of the American Medical Association found that people who ate a classic Western diet—lots of red meat, dairy, sugar and refined flour—were three times more likely to have a colon cancer relapse or die than those who consumed mostly fruits, vegetables and fish. Researchers believe the fatty diet increased insulin levels, which can lead to the formation and growth of certain tumors.

Out of 1009 patients studied, 324 had cancer that returned and 233 died. The study’s lead author, Dr. Jeffrey Meyerhardt, says more research needs to be done in order to understand exactly which parts of the diet were responsible for the findings.