For completeness and for easy reference (this has been posted in other threads)...
A short summary with an added UD2.0 twist: <div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Lyle have a book out there called The Rapid Fat Loss Handbook, that outline a modified PSMF for crash dieting. It would be optimal for cutting if you combine it with the following:
ABCDE talks about micro cycles, for example protein cycling (to reduce excessive protein oxidation). Here is my modified verison of it:
2 weeks of bulking with a protein intake of 2 grams/kg, then 2 weeks of Lyle's PSFM with cycled protein (3+ grams/kg for 3 1/2 days, then a slow decrease to 1 grams/kg over 3 1/2 days, then begin again). 1 gram/kg is not ultra low. If you are a 220 lbs lifter, that is still 100 grams of protein. All the time lifting heavy [vanilla HST] to stimulate PS and get the hormones flowing.
If you throw in a carb re-feed at the end of the first week on the PSMF, during the low-protein days, you counteract falling metabolism, making the cutting more effective, while preserving protein. The carb re-feed could be 4 h, 12 h, or 24 h. It is like putting UD2.0 into the mix.
Phew. We end up with ABCDE-PSMF-UD2.0 with protein cycling while on HST. How hard could it be?
</div>The UD2.0 twist to the 2 weeks of cutting is primarily for performance leverage when lifting weigths, to counteract complete glucogen depletion during 2nd week on ABCDE. We do want to lift the weigths!
And on the foundation of calorie cycling for packing on lean mass and shedding fat: <div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">Actually the problem is, that if you are only eating maintenance calories, you will grow very very slowly. If you up your calories you both gain muscle and fat. Then to become lean you must perform some kind of dieting to loose the gained fat. This is the basis of calorie cycling. That we all know. Nothing new. But then it is a matter of how long each cycle should be. 6 months bulking followed by 6 months cutting are perhaps normal, but is it effective? As you yourself hinted at, will the body adapt to certain levels of caloric intake? We all know that constant dieting will slow the metabolism down. Constant bulking is unhealthy. You risk develop insulin resistivity and high blood pressure. You may gain so much fat that adipose tissue undergo hyperplasia and you develop obesity.
So, what is a more sensible approach to stay ahead of adaptations? Shorter cycles. The intermittent fasting (IF) idea is the shortest of them all. Eat 12-24 hours, then fast 12-24 hours. Will it work? Probably. ABCDE diet proposes 2 weeks bulking followed by 2 weeks cutting. Will it work? Most probably.
Any other diet idea [with the goal of packing on lean mass and shedding fat] will be based on the same premises. You may adjust the length of a phase to achive different results. Doing more bulking will eventually make you fat, while doing more cutting will eventually get you ripped but not very musclular. Balance these phases out is the key, while using all the advantages weight lifting can get you.
Then, if you start out with, for example 15% BF, how will you make it drop off while packing on muscle? Most would argue to diet down to 10% BF and then bulk to 12-13%, and then diet down to 10% again. Bulking up to 20-25% BF just to grow big and muscular will make it so much harder on you (and you probably won't be so impressed with the reflection in the mirror either). The lean mass you have gained will be hidden from view. Surely not the best way to go. </div>
And what to do when doing a SD: <div></div><div id="QUOTEHEAD">QUOTE</div><div id="QUOTE">I think during the SD it's best to eat maintenance, because the lack of workouts will not do well with the P-ratio (either bulking or cutting). </div>
To sum up thinking:
A full 2 week/2 week cycle might be a bit excessive, but however workable if we throw in UD2.0. But to make this even more practical I propose that we shorten the cycle to a 1week/1week cycle. Why? You will not need the UD2.0 twist. With the UD2.0 twist, after 5-6 days of PSMF, while doing HST, you will be glucogen depleted and your metabolism have begun to slow down (leptin levels at 50%). A short UD2.0 carb up on day 7 may not boost your metabolism enough so the next week would not be fully optimal (you are no longer so far ahead of the adaptations). On the 1w/1w cycle you continue cutting the full week and then hit your bulking week instead of the UD2.0 carb up. Your metabolism will be forced to go up from a steady supply of energy. I think it makes more sense.
So, for optimal (and practical) cutting/bulking PSMF/IF we have a time span of 1-7 days bulking, cycled with 1-7 days of cutting. Any longer than that and some things may no longer be optimal (or practical). Any shorter and the cutting/bulking will be blurred into a 'far-in-between-meals-type-o-thing'. Surely it works to some extent, but is it optimal? In the end, you yourself will find out what length of the cycle will work best for you (both optimal and practical).