I'd guess something like 7-8% BF if you're a man, and 11-12% if female would start to drain the FFA's. You should try to get a blood test confirmation of that but otherwise I'd guess staying there for 3-4 months and not having much dietary cholesterol in that time would get your Insulin resistance gone for good.
There on you could go back to your regular diet, and may have no serious weight gain.
Insulin, leptin and ghrelin and all other hormones would need to match up to your weight. That will be where you're going to be longer term.
Again, this is pure hypothesis, no one, not even Dr Fung appears to have fasted someone to the state I'm talking about let alone keep them there for any length of time.
I briefly went to the low 140's. I didn't spend much time there at all. I need to get my experiment done proper, so I'll know what ends up happening.