1,000 calories is a starvation diet and although there would be a feast on the weekend, I highly doubt anyone is going to think and work or perform properly or grow optimally while being on a starvation diet for more than half the week for weeks on end even if they indulged on weekends.
I'm not saying this in a dick way at all, nor am I concerned with what some other guy's nutritional experimentation. But it just seems that these propositions are odd. I mean, who is going to do this sort of stuff? Why would someone use (or perhaps waste) their time with such stuff if there is a far more reliable way of doing things, a way that has been shown to get results time and time again?
It reminds me of IIFYM experiments taken to the extreme. "If I eat just the right amount of pork rinds and sugar and take a multi-vitamin will I be straight?"
The approach you describe also creates a hassle. Sure, on a cutting diet, for most people, they can't just unduly keep decreasing calories with no refeed or high carb/calorie day; so that's why a weekly review of caloric intake would be of benefit. But the approach you provide is extreme, and as I said, for 5 days of the week is providing a starvation diet, really not what someone who wants to grow and perform and think straight should be doing. I'm not one for musclehead cliches but that is not an "anabolic state".
I'm not educated on it, but I THINK Scott Abel's Cycle Diet involves something LIKE what you say here. So is the Rapid Fat Loss Diet, which I used years ago and made a thread about in the nutrition section which spawned RFL 2.0 to RFL 4.0 threads. If you are left with 1000 calories per day, nearly the entire diet will be protein. If I recall correctly, my daily intake on RFL was 1,200 to 1,300 calories per day. Ever try getting through life, let alone workouts, with that? The diet DOES WORK, but it was a miserable experience and all those close to me who used it had success but said they don't think they could ever do it again.
Are you going to try this?