Overweight and colorectal cancer risk.

Epidemiological studies on risk factors for colorectal cancer have focused mainly on diet. Weight and height have also been studied, partly because they reflect the balance between energy intake and expenditure in different age periods. Energy intake, body size, physical activity and colorectal cancer risk will be reviewed in this paper focusing mostly on recent data coming from Italian, English and Scandinavian studies. Overweight has long been recognised as a risk factor for hormone related and other cancers, including colorectal cancer. In addition, the epidemiological evidence consistently shows that physical activity reduces the risk of colon cancer. On the contrary, evidence on rectal cancer is less impressive. In conclusion, body size control along all life and physical activity represent important factors to prevent colon cancer and a wide range of chronic conditions. Therefore, strategies to favour these goals through counselling from health-care providers, regulatory changes, and programs aimed at individuals and communities should be implemented.