How did you go about taking the cast and crew of "300" with higher body fat compositions and thrash away the dead weight in the time frame you had? Specifically that of Vincent Regan which progress pictures show a ridiculous transformation in the span of week 1 - 8 that you showed. Granted he more then likely had week/ day/ hour/ minute/ second focus. How did diet go hand and hand with training?
I was glad to read your interest in going the opposite direction from gaining mass since I find it more complicated and interesting, and it is likely more useful for most. That you referenced "week/ day/ hour/ minute/ second focus" was refreshing because it shows me that some people assimilate what they read on the site and put it to use, which means we have done some things right.
Vincent is not an extreme example of the pattern of fat loss on that job but he did consent to have us follow him more closely and he had (perhaps) the greatest recomposition challenge of the 35 people we trained on that job. After I first met him I told the director, "I'm good Zack but Vincent needs a miracle ..." Happily, Vincent had a strong work ethic - developed by growing up in rural Ireland - and resonated well with the training itself and my personality, which were two strong factors his transformation, and apart from the diet.
Diet was critical. First though, it must be recognized that what Vincent did was radical. And radical cannot be maintained. It was a short-term intervention to achieve a particular goal in a limited time frame.
Key factors in the program:
Calorie-restriction (and the discipline too maintain it): Vincent was eating about 1800 calories a day
Quality food and "adequate nutrition": we had a kitchen on-site and provided all meals and snacks, it wasn't all organic and healthy but there was no junk and each individual received a balanced diet, with emphasis on fat and protein.
Zone ratios: whether the Zone diet (40% carbs, 30% protein, 30% fat) works for the reasons stated by its inventor or for other reasons, eating those macro-nutrient ratios, and following the caloric recommendations based on the protein requirements of lean body mass, tunes the body to fat metabolism and strips excess off in a hurry - especially when combined with high-intensity exercise.
Training volume: Vincent trained with us 60-90 minutes/day five days/week, did his fight training about two-hours/day, and ran for 30-45 minutes each weekend day. Call it about 18 hours per week of volume, which would total over 800 hours per year if sustained and that's in line with a nationally competitive Nordic ski racer (though not internationally competitive). Even 600 hours annually would be huge volume for most individuals.
Training intensity: Vincent's only low intensity efforts were the weekend runs, everything else was does at very high intensity (measured on an individual basis because what is intense for some may be either crippling or too easy for others). So, post-exercise energy consumption was significant. His metabolism was going high-speed for many hours after the training.
Constant supervision: the training frequency meant we had eyes on him every day, spoke with him every day, knew when he was slowing down or breaking down and adjusted training and calorie intake accordingly. Because of his history of physicality, again the rural upbringing and farm-work as a kid, he could sustain greater, and more consistent output than most but we still had to be very aware. I think this is the most critical issue to the process. Many, if not most radical dietary and training interventions will fail because the program is followed by rote and not adjusted according to individual adaptation or response along the way. At some point it will simply be too hard to continue and the dieter will fall off the bus. The pendulum never stops in the middle so when the fall happens it's a long one. Coaching is important in a cajoling, reinforcing, whipping, carrot-stick sort of way for both eating and training.
Again, what Vincent did was radical and sustainable in the short-term only. We probably went longer than we "should" have but being in his face every day allowed it.
Long term dieting often fails to recompose the body in the desired way because the body adapts to a consistent calorie load, and if it is too low the metabolic rate will be down-regulated to match intake. This can be overridden with training to a point. Managing the diet in a similar way to training can also help: high intensity (radical restriction) for three weeks, then a week of easier training or eating. About three weeks into the restriction is when the body starts adapting the metabolic rate to match caloric intake, etc. so that's the time to trick it into doing something else.
One final note is that many of the guys on that job could not get their heads around the idea that eating fat doesn't make you fat. Dan John and I were joking yesterday about high-fat diets, "try gaining weight on a diet of steak and butter." It can't be done. Both protein and fat consumption triggers enzymes signaling satiation and only the truly disturbed can force-feed themselves after those chemicals are present. One can trick oneself of course by speed-eating to get more calories in before the satiety enzymes are released and apparently many in our society have this ability.