When you move to a foreign country, conditions are always somewhat different than where you came from originally. The weather, the food, the customs and routines probably won't be the same. So obviously your body behaves differently and sometimes it takes a while (lets say a few years) for you to tune your ear to what it's saying and to adjust completely to your new environment.
Coming from a very sunny country, I find I need vitamin supplements (especially vitamin D) to keep me going through the day. If I fail to take then I'll get SAD (Seasonal Affecting Disorder). It sounds like a posh name for something meaningless, but trust me, if you don't take care of it it can get pretty big pretty fast! Also, because I'm used to higher temperatures, it's sometimes tricky to keep my daily water intake, because here I hardly ever feel thristy. Right now I'm a bit under the weather - constant sneezing or feeling like I'm about to, nose clogged up yet feeling runny, voice damaged but not exactly hoarse. So I started treating it like it was a simple cold. Now, after three nights and two days of it it's beginning to dawn on me that it might be allergies. I've never had them in my life, but since my living conditions have certainly changed, this might be a first of many!
To some extent, sometimes it's just easier to forget what you know and restart your system entirely. Just create a national default mode for your newly adopted country. Open your eyes and learn the way of the land. Learn from the natives, after all they've been living here a heck of a lot longer than you! Just get it into your head that "resistance is futile". New country, new way of living. Make that your motto. I've kept some aspects of my old life (a few recipes, a handful of daily routines, etc) but most of it went out the window. It had to. And now I'm all for learning a new way of living, by trial and error if it must. Me and my body learning along the way. Hey, maybe I can even turn it around and introduce some new ingredients in my life. And God knows some of them have been long overdue!