Did you know that what and how much you eat can affect your risk of developing certain cancers? According to the American Cancer Society, about 20 percent of all cancer diagnoses in the United States are linked to diet and excess weight, along with inactivity.

Much of the research linking diet and cancer is “substantial, yet inconclusive,” according to the World Cancer Research Fund (WCRF) and the American Institute for Cancer Research (AICR). That’s because it is very difficult to establish a definitive link between cancer and specific foods or nutrients. Most findings come from tracking dietary patterns in different populations.

The WCRF and AICR issued cancer prevention recommendations as part of a report first published in 2007. Their findings were based on a review by an international panel of scientists of studies related to the connection between cancer risk, food, nutrition, and physical activity. The following are some key dietary recommendations based on that report and other cancer research.