Yup. I fought in the cage 4 times, although I train pretty exclusively in Brazilian Jiu Jitsu and do just enough pad work to try to be able to avoid getting hit long enough to clinch (uh oh, now you know my secret strategy!).
I made weight for the fights by eating a HFLC version of Primal, with IF. Lots of dairy for me, because I tolerate it well, Fatty meats, eggs, leafy green veg, occasional sweet potato.
Now, I'm training for a powerlifting meet, and am alternating between HFLC days and LFHC days, but I still get to the Jiu Jitsu Academy 3-4x/week. I feel awesome, am quite lean (10%ish body fat), and keep setting PR's with the barbell while making my training partners' lives more miserable.
I'm not even that young. I'm 32.