I tend to believe our bodies are smarter than us and if you're following hunger signals it just doesn't seem likely to me that your body would put itself into that situation to need to reduce metabolism by choice.
Don't forget, the fat we have stored away is there for exactly this reason. To be used when needed. On a high carb diet, not our natural diet, our bodies have a hard time switching over to using fat so it mostly doesn't. It makes you hungry again so you'll feed it sugar because it doesn't know how to access the fat. Now that you've taught it how to use fat for fuel, it's doing it quite nicely.
This is an incredibly common question and I can assure you, based on what has happened to so many of the rest of us, once you've used a certain amount of body fat, your body will increase your hunger signals and you will naturally eat more following those signals. This will happen way before you're ready for your body to stop using so body fat. lol
Then you'll be actively trying not to overeat.

Also, if you don't know about your increased needs for sodium, please find the post about electrolytes in the FAQ.