I don't think I would have the drive to do it, but take a look at this.
Calbet, JA et. al. A time-efficient reduction of fat mass in 4 days with exercise and caloric restriction. Scand J Med Sci Sports. 2014 Mar 6. doi: 10.1111/sms.12194.
subjects weight stable for at least 3 months, all between 20-40% BF, age 18-55
5 phases--phase 1, normal activity, phase 2, 4-day intervention (the actual fast), phase 3, 3-days of a normal diet and limited activity, Phase 4 was four weeks where subjects could eat and exercise by their own choice and Phase 5 was a one year follow-up.
phase 2 was the meat of the experiment. severe calorie restriction and lots of exercise. subjects were given 3.2 kcal/kg (1.4 kcal/lb), appr a 90% deficit. (DAMN) AND they did arm crank exercise for 45 minutes and walked for EIGHT hours. Real low intensity (DOUBLE DAMN) The calories were either all protein or all sucrose. OK, only 4 days but holy crap.
Fat Loss LBM Loss
Phase 2 (4 days) -2.1 kg (-4.6 lbs) -2.8 kg (-6.2 lbs)
Phase 3 (3 more days) -2.8 kg (-6.1 lbs) -1.0 kg (-2.2 lbs)
Phase 4(4-week Follow up) -3.8 kg (-8.4 lbs) -0.5 kg (-1.1 lbs)
Phase 5 (1-Year Follow up) -1.9 kg (-4.2 lbs) -0.4 kg (-0.88 lbs)
weird that there was nearly no difference between the protein only or the sugar only groups. also weird is that the research indicated that the majority of the loss was from the trunk. Might that be because the limbs were active?
Questions for you
Could you do this if you were compensated? (that was my first thought)
2nd, have to wonder if higher calories from quality protein (2x or so allowed in this study) and a big reduction in the work performed would change the amounts or percentages of mass lost.
3rd, for bigguns, the 30+% BF folks, would this be repeatable and effective? 4 days on the "intervention" and a good amount of time on stabilization and recovery? I mean, go after it balls out, long enough to have impact and short enough to not throw everything out of whack, and repeat twice per month? Of course under supervision. OR weekends for a month?
I'm just an insomniac and am still up at 515am Dallas time.