I have been doing keto for about 2 months and have tried some IF the last three or four weeks, mostly 16 (or 18): 8 by skipping breakfast. A few days last week I also skipped lunch and limited my dinner calories to 500 (I am female). So I guess I'm doing 16:8 combined with some 5:2. It is going very well. I found out a couple months ago that I was showing signs of early insulin resistance, and already with this new lifestyle I am seeing major improvement. And I'm also losing weight! Bonus! Here is my question: should I vary things a little? If I skip breakfast every single day, won't my body just get used to this and then make the fasting regimen less effective? Should I have breakfast some days just to shake things up a bit? I think I remember reading something from Jason Fung about having a little variety in the routine- but I have read so much that my brain is fried!