There have been some recent rumblings about the ingestion of saturated fat, particularly butter, having a negative effect on insulin sensitivity. The study demonstrating this affect is discussed in the Lopez et al paper. I think there are some aspects
Saturated Fat and Heart Disease
A meta-analysis shows there is no significant evidence for saturated fat being associated with CVD. Siri-Tarino PW, Sun Q, Hu FB, Krauss RM. Meta-analysis of prospective cohort studies evaluating the association of saturated fat with cardiovascular disease. Am J Clin