Hey Pooh,
Add 200 grams of extra carbs a day to your diet for 4 weeks. Get in the UW weigh tank before and after. Then lose the fat. After you're back to baseline, add 200 grams of extra protein to your diet for 4 weeks. Check it again. Let me know if the results are the same. Bet they are not.
I'd adjust protein to LBM. Pooh is correct, any kcals above what is expended with be stored, although protein is the most labor intensive for the body to convert to fat. Thus, if you're bodyfat is high and you base your protein intake on total body mass, it may be too much, or comprise too high a percent of your total calories.
W6