A case-control study was done to examine the relationship between childhood and recent eating practices and risk of breast cancer. Eight hundred forty-six cases and 862 controls returned questionnaires indicating their menopausal status. In premenopausal women, breast cancer risk was increased with recent consumption of foods high in fat content (gravy, beef, pork) and reduced with foods low in fat content (fish); in postmenopausal women, risk was increased with pork consumption only. Regarding carotene sources, risk was reduced with carrot consumption in postmenopausal women only. Similar trends in risk were not found for childhood eating practices. Body weight influenced the breast cancer risk differently for pre- and postmenopausal women: Heavier weight in childhood and teens reduced the risk of premenopausal breast cancer, and heavier weight in adulthood increased the risk of postmenopausal breast cancer. We conclude that fat consumption is associated with breast cancer, especially in premenopausal women.