Very good point, I kind of knew that, but seeing it written by someone else makes it even more special. Tnx ;)

Yeah, you can find nice business casual clothes to wear. It sounds like they aren't even asking him to wear a tie. How you present yourself is very important.

This is "more of the same" - so adding as a comment. The right thing to do is probably to state that you understand their concerns and will work, gradually, to improve the situation. Then start dressing well. Maybe start spending on lunch. Drop it the bucket compared to rent, which you could probably stick with if you take care of the other items.

I think the fact that the approach was delegated to a lady- I am carefully avoiding saying girl here- is significant. They're trying to give you advice about how to fit into and progress within the organisation and your profession as a whole, and points about dress and social integration are ones that have to be made to many people at some stage of their career: the sooner the better. On the other hand, pressure to move and live somewhere by yourself is unwholesome, particularly if you rely on your housemates for social interaction... which I suspect you do if spending hours a day travelling.

This answer is very old-school, why not also say that OP needs a good firm handshake and to dress for the job he wants and not the job he has? OP does not want to be "successful", whatever it may mean, he has his work and his life and is satisfied with both. Why not address the heart of the issue: OP is having a conflict and seems ready to push back on those expectations. What is the diplomatic way to do this and what are the risks?

The eating is important, not (ever) going to lunch with your colleagues is going to be considered standoff-ish. I would go at least once a week, even if you mentally file it as "work" and not "break".

@Johan.... This is telling the OP what they probably need to do if they want to keep their current high paying job. There is nothing wrong with dressing professionally to go to work. In fact it is generally speaking expected.

@Johan Your comment seems to assume that there an equilibrium has been reached between employee and employer such that if OP changes nothing, nothing will change. The employer's has obviously expressed that this is not the case. I don't see this answer mention anything about being successful.

"I'm in a minority group wherever I go in the World." Even though I don't entirely agree with the answer, I'm going to trust you on this basis.

@Johan If OP likes his current job and the pay it gets from it, then his version of "being successful" may be "keep the job I have". But he's being challenged on that success goal by additional demands, and he has to understand how to deal with those if he wants to "be successful".

@Questor and Simone: I somehow agree with you both, but I think you are reading more than what is written. This answer boils down to : "I think dressing for work is the norm and I think you should follow the norm." Why? What are the risks if not w/ German labour laws? Is it the norm in the particular sector (research) and culture (germany) OP works in? (from my experience, it isn't.) Can they hope to find a more accommodating company? Or should they try to negotiate on those expectations and contact their union if any? So much questions not addressed by this answer.

This answer only mentions the clothes, but that's just a small part of the question. The OP was told to rent a more expensive apartment and to eat more expensive food. What should they do about that?

@Nohbdy Odd that you seem to think it's me who values social interaction, I never said that. I know from experience though, that a lack of social interaction for whatever reason (shyness comes to mind) gets - on average - interpreted as arrogance and that can cause problems at work.

@Marianne013, your suggestion to immediately capitulate tells me that what you know from experience REQUIRES capitulation rather than meaningfully respecting people's wishes or boundaries. If anything other than the work, basic decency, and respect for others is causing problems at work, there IS a culture problem, and it's almost certainly not with the quiet one who is working instead of socializing. Introverts don't need to be fixed, and extroverts shouldn't be the default benefactor of social expectations. Tackle THOSE problems.

@Marianne013, make no mistake, I'm not trying to make this personal in any way. Everything worth doing is worth questioning, and if you aren't willing to burn down your assumptions and set fire to your comfort zone, you didn't question it enough. How many terrible engineers have jobs because they 'fit'? How many bad doctors? Bad professors? Bad managers? Fit be damned, especially when the people making that call are pushy, arrogant extroverts who can't conduct their own technical interviews because they aren't qualified.

@AaronF thats just filler. Food and living arrangements are personal concerns. Appearance isn't. So if the OP meets them halfway with the presentation, no one cares about the rest. Problem should never have arisen to begin with. You don't go to another country and make no effort and expect no repercussions either at work or socially. People from poor countries should be well aware of this, because the poorer the country the more important appearances are.

@Questor "dressing professionally" unless there is a uniform or a dress code, what does that even mean?

From a perspective in German research, I see this answer with - at best - incredulity. OP is a salaried employee with a contract in which their duties are clearly outlined. Asking employees to join team lunches is understandable (though probably still illegal if it counts as break time). Requiring OP to change apartments, on the other hand, is really just a very juicy lawsuit waiting to happen. If you believe employers should have such invasive rights, that is your prerogative, but please be aware that what is friendly advice to you can be borderline insulting to others.

@Nohbdy "capitulation", "setting fire to", jeez, I don't know what you are doing, but I go to work and not to war.

@MarcVaisband you either didn't read the unswer or misunderstood it. I don't advocate the OP changes apartments or has team lunches.

@Marianne013, then congrats! You're probably an "in" group. I'm not. I live quietly in the closet in Texas where my employer (the CEO!) is cheering for fascists. I served in the Navy under "Don't Ask Don't Tell," which is a hell of a time to find out things about yourself. I was told to take my own life, daily. All I want you to do, is nothing. Leave folks alone, and if you have it in you, push back for the ones that really just have nothing to say. They'll appreciate it.