This is one of those deals where less turns out to be more. Let’s say you’re rolling right along in your normal pattern of eating protein to more energy and build muscle. Then, once every six days you decrease protein to .5 to .7 g per pound of bodyweight while increasing carbs accordingly (a 200-pound bodybuilder, for instance, would take in an additional 60-100 g of carbs to make up for what he is losing in protein on that day of protein reduction). This sudden drop in protein sets off an internal alarm that shifts the body into a protein-preserving mode to guard against deficit. Once you return to your standard protein intake, you’re more likely to add more muscle mass because the body continues to produce the enzymes and hormones triggered by the one-day protein drop.
One day of low protein will not force the body to preserve protein. It will take more than one day to see a decrease in gluconeogenic enzymes resulting in protein synthesis that will be decreased on this day, but protein degradation that will remain constant, so you’ll just use up liver proteins and the available protein in the amino acid pool. You’ll also have glutathione levels drop as well. During starvation in rats, the first proteins to be lost are from the liver, with 25-40% of liver protein being lost after 48 hours. So it make sense to think that liver and organ proteins will the first to be replaced, and by the time muscle proteins are replenished the body will have adapted and no net gains in muscle mass will have occurred.
EA Oddoye, and S Margen found that when subjects switched from high to low protein intakes, there was a large negative nitrogen balance which lasted for about 9-12 days before the body adapted.
You could try a 3-4 day low protein period followed a similar high protein period, but I doubt the overcompensation during the high protein phase will amount to any more net gains than if you had ate the same level of protein all the way through.