Fatty acid composition of membrane bilayers: Importance of diet polyunsaturated fat balance

► An extensive study of influence of diet fat on membrane composition in rat tissues. ► Membrane SFA, MUFA and PUFA homeostatically regulated irrespective of diet variation. ► Adipose tissue and plasma triglyceride composition are highly responsive to diet. ► Membranes respond biphasically to balance between diet n−3 and n−6 PUFA. ► Important health implications for diets with n−3 PUFA < 10% total PUFA.