I think the advice to favor unsaturated fat in the diet will ultimately be regarded as being as misguided and dangerous as the old, now discredited idea that margarine is healthier than butter. Unsaturated fat is nowhere near as chemically stable as saturated fat and is far more prone to peroxidation by free radicals than saturated fat; polyunsaturated oil is a huge oxidative load on the body, and modern diets contain far more of it than just the necessary small amounts of Omega 3 and 6 essential fatty acids.
Our mothers breastfed us saturated fat. Our bodies store fat as saturated fat. Saturated fat gets blamed for our ills, yet over the past 100 years, consumption of traditional saturated fats is way down while at the same time, consumption of polyunsaturated seed oils is way way up. The overload of all that inflammatory Omega 6 laden seed oil is why people are now scrambling to get enough Omega 3. Inflammation is implicated in both cancer and heart disease. Additionally, these chemically fragile polyunsaturated oils are being subjected to high temperatures during manufacture and cooking, which causes unhealthy oxidation and polymerization.
Personally, I'm more inclined to favor the traditional fats that our species evolved on rather than the fats found in relatively new agrarian diets based on seed crop monocultures. For more on that perspective, see:http://www.westonaprice.org/knowyourfats/