I don’t think one loses fat adaptation so easily but of course I don’t know what it takes to lose it and I just suppose things, it’s not like I could ever measure if I was fat adapted… I just used my experience. I suddenly changed after 7 weeks on keto and I suppose that was my fat adaptation (some basic level, at least). I never ever lost the benefit I got during my on/off keto years but sometimes I felt it’s not so great so I dropped my carbs again. I didn’t do high-carb weeks after I went low-carb but one high-carb day or low-carb weeks happened, they were seemingly fine. But this is me, I don’t know how it works for others.
Losing my water weight changes may be my other level of fat adaptation, maybe? I don’t gain any weight if I suddenly eat a lot of carbs. I never lost this either I think but surely not for years, I stopped weighing myself as my weight is almost always the same.
Even if you lost fat adaptation, you still have the experience with keto. Your body probably “remembers” it too. You have keto habits, maybe not strong ones, I don’t know but you have practice. As time passes, eating less carbs are way easier for me and having carbier times don’t seem to have an effect (if I overdo carbs, eating less carbs gets loads easier, actually the only option but I try to avoid that, sugar poisoning isn’t fun and it’s rude to my body anyway).
But I can say… You can’t change the past. So do the best from now on…? I would be curious myself but what you should do, that isn’t affected by the answer. Drop your carbs and give your body what it wants. If your body is smart and likes keto, at least. Mine always wants something close to carnivore, it’s my other parts that make me stray away…
And I’ve heard that even if one isn’t fat adapted yet, eating off doesn’t undo ALL the work. So it’s not that simple to undo all efforts
The girlfriend issue… It’s so odd to me. It shouldn’t matter what she believes in or prefers (maybe a tiny bit) as it’s not her woe and life and health. And it’s not even some experimental “it feels strange but I give it some months” change, you already feel BETTER. Isn’t it make thing clear? Your body loves it, you should do it?
And you have all the right to decide what, when and how much you eat - at least as long as you don’t do something extremely bad. It’s something very personal, it’s odd to me people don’t see that. No one ever should be offended I don’t eat something but I have a responsibility to have an okay woe, not something that damages or hurt me. She can’t expect you to hurt yourself for her… It’s not love IMO. I don’t know how she thinks but I surely would talk about things with her. Maybe she would understand or at least accept. One should respect the other person and their dietary choices. Discussion is fine but coercing someone to give up their well chosen woe even for a short time…
If I go off keto, I wanted that. It’s still not necessarily good but at least I made a decision about my own diet.
Most of us was raised on high-carb and bad stuff. We can learn and change.