Essential fatty acids (EFA's) have been shown to have positive effects on insulin sensitivity, thermogenesis, anabolism, and much, much more. These processes entail the use of many complex mechanisms, however of prime importance is their function in hormone synthesis. By passing through the cyclooxygenase, or lipoxygenase enzymatic pathways, fats are able to form several hormones known as eicosanoids. These hormones elicit many anabolic attributes. So in short, your missing out BIG TIME if your failing to include EFA's into your diet.
There not very expensive, you can buy HEMP OIL at proteinfactory.com but I prefer UDO's EFA blend myself. But either will sufice.
I'm also gonna make another thread about EFA's b/c I think many will benfit from it.