About a year. Pretty strict Primal but without serious regulation of cheese, wine, or nuts. I lost 20 lbs in the first 4 months, which took me 10 lbs below my goal and to 11-12% BF. Maintaining pretty easily since then. I have almost certainly gained some muscle throughout. None of it has been particularly challenging. The weight loss just happened. I am now in that curious mode of playing with different things just to see how my body reacts. All in all, I am completely happy with where my body is; not too bad for someone who turned 53 today.