Background: I started Primal in January pretty sugar-strict. No fruit at all, no nuts (but still peanut butter a couple days a month), some dairy. Pretty much just meat and vegetables and butter with some cheese and heavy cream. Lost a bunch of weight really fast. In April my diet started slipping. Started having a square or two of 85% chocolate every day. Plateaued for a whole month. Started working out super hardcore and stopped the chocolate and lost some more more weight. Then, not long after, I plateaued again for another whole month when I started eating fruit. Mostly cherries and bananas. Not even every day, but apparently often enough to stall out. I was doing a lot of walking during this time, so I don't know what caused it if not the fruit.
A week ago, I made the decision to go full keto, basically like how I was doing in the beginning. After dealing with some BAD sugar cravings for a few days, I've lost 5lbs again, and I'm expecting a few more pounds by the end of the week.
After two rounds of this, it's pretty clear I just need to stay in keto. And I'm still avoiding nuts mostly, but I have been eating 2 brazil nuts a day for the selenium (I figure it's better to get it from a whole source rather than take pills).