COMIDAS Comparing Original Mexican Diets and Standard US Diets

Participants will be randomized to an isocaloric Indigenous Mexican or a Western diet for 24 days. All foods and beverages will be prepared by the Human Nutrition Laboratory at the Fred Hutchinson Cancer Research Center. After a 4-week wash-out period, participants will cross over to the other arm and be given the alternate diet for 24 days. Blood and urine specimens will be collected before and after each feeding period to test baseline and post-intervention metabolic response as defined by various inflammatory and cancer susceptibility biomarkers including insulin-like growth factor 1 (IGF1), insulin-like growth factor binding protein 3 (IGFBP3), leptin, adiponectin, interleukin-6 (IL-6), C-reactive protein (CRP) and SAA (serum amyloid-A). DNA extracted from whole blood will be used to test whether a panel of 128 Ancestry Informative Markers (AIMs) is associated with metabolic response to the diets and other phenotypic traits of obesity, which relate to breast cancer risk.