xrissy,
If your goal is to put diabetes into remission, I believe the 800 calories v. 1200 calories is a critical difference. If your goal is weight loss, not so much.
I’ve been eating 1200 calories a day since October 2 and have almost certainly been in ketosis most of that time (although it is not a specific goal of mine, so I don’t check). I’ve eaten fewer than 50 carbs most days (although my specific limit has been fewer than 20 in a 3 hour period. During that time I lost around 50 pounds, and never moved beyond management of BG. Even with 50 lbs down, if I ate something with more than 20 net carbs, my blood glucose shot up just as much as it did on October 2.
Nearly three weeks ago, after reading Dr. Taylor’s research, as well as doing research on fasting and insulin, I started the BSD fast 800 + 16:8 intermittent fasting. The goal of both is to restore my 1st phase insulin response, and put my diabetes into remission. In the second week I had a meal that contained 33 carbs and nervously tracked my blood glucose for 3 hours – the peak was 6.16 (111). Little more than a week earlier, 33 carbs would have put my BG over 7.8, and likely closer to 10.0. So, I achieved – in a little over a week at 800 calories – something I was unable to even approach while consistently eating low carb/keto at 1200 calories for 6 months. (Even with the stress of multiple doctor’s visits this wee testing for what is almost certainly breast cancer, my average BG is still under 5.6 (I believe 5.4, but I left my meter at work). My average for the preceding 3 months (on a ketogenic, 1200 calorie diet) was 6.
The difference to me is remission (meaning I won’t have to actively manage my BG by dietary control) v management of BG by careful monitoring of every bite I eat. 1200 gives me the latter; 800 gives me (I hope) the former.
But – if you’re not going for remission of diabetes – it probably doesn’t matter.