Weirdly I don't think losing a little weight is sustainable in the long run.
I'll explain why - but since I am not a doctor, this may be rather 1/2 assed and incoherent not to mention wrong.
I got from 40% BF to 20% BF. You body has had to burn all that fat, that's pretty much like being on a diet of pure fat for months. That has the effect of getting your free fatty acids very very high. That makes your insulin resistance worse. Since that is a key factor in setting your weight, you are now primed for getting to a higher weight set point than before.
I was 186 or so before my weight loss. I lost 70+ and my cholesterol was 206.
The only way to get sustainable weight loss is to get that 186 to 140-150. Which will not happen when my body is eating its own fat. If @ 20% BF I returned to my normal diet, adjusted for the lower weight and hence lower calorie need, I will pretty much get back to 40%BF which was ~238lb.
To lower your Insulin resistance, you need to lower insulin and lower FFA's which means you have to finish using up all the fat, then a few months of low dietary FFA, so your body has no FFA's from any source. I almost suspect at that point I'd have naturally lowered my appetite to where its good and appropriate for my size (which is leptin sensitivity), as well as got rid of my Sugar
cravings which is also insulin resistance.