Inclusion criteria:  Genetically-defined HeFH Premenopausal women with a regular menstrual cycle for >3 months Postmenopausal women (without hormone replacement)  Exclusion criteria:  Any cardiovascular disease-risk exacerbating conditions (age >60 years, homozygous FH, personal history of cardiovascular disease, diabetes/anti-diabetic drug use, severe obesity, unstable body weight for >3 months, uncontrolled hypertension, genetic hypertriglyceridemia), Allergies/aversions to components of the experimental diets Any condition that would interfere with optimal participation in the intervention.