Scientists have discovered that fat is essential for good health. They've also determined that there is no such thing as a "good fat" or a "bad fat." All fats are good. But if the balance of fats is inappropriate, then that leads to body failures (chronic disease). The balance of essential fats (the ratio of Omega-6 fatty acids to Omega-3 Fatty Acids) in the membranes of the cells in our bodies should replicate that of green leafy plant material. That ratio hovers around one to one. When the ratio is skewed, for instance when it's greater than four to one, body failures start to occur. This is why the meats you eat must have ratios that are very close to one to one. Even four to one is unacceptable.
For additional reports on the nutritional characteristics of grass-fed meats please visit these links.