Intervention: Patients will be introduced to the intervention diet by a dietitian and will receive general information about healthy food choices (according to recommendations for the general public) and not to eat any dietary supplements, no other dietary restrictions will be given. The patients will be given a package containing food with a high amount of phytoestrogens (≥100 mg isoflavonoids and ≥100 mg lignans) that are to be consumed daily. The intervention continues until the day before the surgery (at least 6 weeks). The patients in the control group will be informed in the same way as the intervention group except that they will not receive any food-package.