Carleton- i suspect you and i have similar difficulties getting into Ketosis. For me the only way to turn the strips anything resembling dark purple is to really up my fat intake..
Check out this Keto Percentage calculator:
http://keto-calculator.ankerl.com
Even if i am quite conservative with my entries i still get a daily fat requirement of 200g
200g of fat is nearly a 1/2lb… that is the equivalent of an entire block of Kerry Gold butter- every day- day after day.. its a lot of fat and i suspect the "I'm eating lots of bacon and butter" diet doesn't get us close- maybe some days, but not week after week..
Im trying to track down the study- but there is some solid data that says that when you put people on Atkins and tell them to eat "all the fat they want" they end up limiting themselves to quite low daily calorie intake.. we are not accustomed to eating that much fat..
I have found that the only way for me to stay in ketosis (and keep the sticks purple) is to consume well over 100g of Medium Chain Triglyceride fats on their own throughout the day.. so spoons of Virgin Coconut Oil and shots of Olive oil.. thats in addition to fatty meats, bacon and avocados..
The counter to this whole thing is- I'm not totally convinced being in Ketosis is even necessary.. I am playing around with it to try to lose a big chunk of bodyweight fast, so i can "Make Weight" at a powerlifting meet (think Vision Quest)- but if i was looking for a more gradual weight loss id just do my normal Non calorie restricted Paleo..