The risk of breast cancer is affected by lifestyle. Obesity is associated with a two-fold increase in risk among post-menopausal women; this has been linked with high intake of meat and dairy fat, but the precise nature of these relationships are still unclear. Regular alcohol consumption (two or more drinks per day) increases risk by about 40%. As with many other forms of cancer, eating more vegetables can reduce risk. Physical activity also seems to reduces risk (in pre- menopausal women, at least), and more intensive activity may produce greater benefits, although this is not yet certain. It seems, therefore, that there is scope for primary prevention, and intervention studies are in progress