There is no hard and fast rule. You have to determine what level is best for you - if you don't feel well on a higher fat intake then you need to lower it. If you don't lose weight on a lower fat intake you may need to raise it. As I've mentioned to others in the forum, it's not magic, it's science - and science is all about the trial and error

Dr Atkins didn't specify fat percentages, but if you're eating on-plan, you should be eating about 5/20/75 (carb/protein/fat). I find I lose better (and feel better) at 5/15/80 - but I'm very carb-sensitive and every little bit will throw me off track.

My recommendation just from my experience is that you should keep a strict eye on what you take in, including measurements/weights (when they say "four ounces of meat" you should be sure you have four ounces, and aren't just guessing, for instance), keeping track of the percentages of carb/pro/fat, and after a week gauge your progress. If you're happy with the progress you're making, then by all means stick with it. If you're not, tweak it a little - increase the fats and see what happens. If that works, you're home free; if it doesn't, fiddle some more.

Good luck!! You can do this