Thats an interesting question,I smoke everyday but usually in the evenings after my kids are asleep,it takes me approx. 2 weeks to get clean, im 6'2" 270. no where near the leaness you have % wise,but everyone is different. I too eat a high fiber diet,as it helps keep toxin down and is just overall better for you. As far as how much THC can be built up in a % of fat I would think that it can be replaced as easily as it is released but thats just my opinion not medical fact.
Just seems like thats how it would be. Just start cuttin back,and drink lots of water which you should be doing anyway.