I was a bit nervous too. But fat seems to really suit me. I did low fat Weight Watchers etc etc. and had to pretty much eat nothing to lose weight, felt hungry and miserable. This just works for me, I feel I can eat a lot, with added fat, never hungry and either lose or maintain. Hope it will work for you too.
Started Primal June 2012 at 148.5lbs, and 5' 1", reached goal weight in 5 months.
Lowest weight 93lbs - too thin. Now stable at 102lbs much better weight for me at my age.
Primal, minus eggs, dairy and a myriad of other allergens.